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authorMatus Fabian <matfabia@cisco.com>2017-08-21 07:05:03 -0700
committerOle Trøan <otroan@employees.org>2017-08-23 07:42:10 +0000
commit2ba92e32e0197f676dd905e5edcb4ff3e1bec241 (patch)
tree4d5eba20eda422bde4e9218834e1b8662a43b001 /src/plugins/nat/nat64.c
parentcfc997ef3da9f406afe5caad99fc98a53aab7a77 (diff)
NAT: Rename snat plugin to nat (VPP-955)
Change-Id: I30a7e3da7a4efc6038a91e27b48045d4b07e2764 Signed-off-by: Matus Fabian <matfabia@cisco.com>
Diffstat (limited to 'src/plugins/nat/nat64.c')
-rw-r--r--src/plugins/nat/nat64.c858
1 files changed, 858 insertions, 0 deletions
diff --git a/src/plugins/nat/nat64.c b/src/plugins/nat/nat64.c
new file mode 100644
index 00000000000..b04901fade4
--- /dev/null
+++ b/src/plugins/nat/nat64.c
@@ -0,0 +1,858 @@
+/*
+ * Copyright (c) 2017 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
+ * @brief NAT64 implementation
+ */
+
+#include <nat/nat64.h>
+#include <nat/nat64_db.h>
+#include <vnet/fib/ip4_fib.h>
+
+
+nat64_main_t nat64_main;
+
+/* *INDENT-OFF* */
+
+/* Hook up input features */
+VNET_FEATURE_INIT (nat64_in2out, static) = {
+ .arc_name = "ip6-unicast",
+ .node_name = "nat64-in2out",
+ .runs_before = VNET_FEATURES ("ip6-lookup"),
+};
+VNET_FEATURE_INIT (nat64_out2in, static) = {
+ .arc_name = "ip4-unicast",
+ .node_name = "nat64-out2in",
+ .runs_before = VNET_FEATURES ("ip4-lookup"),
+};
+
+static u8 well_known_prefix[] = {
+ 0x00, 0x64, 0xff, 0x9b,
+ 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00
+};
+
+/* *INDENT-ON* */
+
+clib_error_t *
+nat64_init (vlib_main_t * vm)
+{
+ nat64_main_t *nm = &nat64_main;
+ clib_error_t *error = 0;
+ vlib_thread_main_t *tm = vlib_get_thread_main ();
+
+ nm->is_disabled = 0;
+
+ if (tm->n_vlib_mains > 1)
+ {
+ nm->is_disabled = 1;
+ goto error;
+ }
+
+ if (nat64_db_init (&nm->db))
+ {
+ error = clib_error_return (0, "NAT64 DB init failed");
+ goto error;
+ }
+
+ /* set session timeouts to default values */
+ nm->udp_timeout = SNAT_UDP_TIMEOUT;
+ nm->icmp_timeout = SNAT_ICMP_TIMEOUT;
+ nm->tcp_trans_timeout = SNAT_TCP_TRANSITORY_TIMEOUT;
+ nm->tcp_est_timeout = SNAT_TCP_ESTABLISHED_TIMEOUT;
+ nm->tcp_incoming_syn_timeout = SNAT_TCP_INCOMING_SYN;
+
+error:
+ return error;
+}
+
+int
+nat64_add_del_pool_addr (ip4_address_t * addr, u32 vrf_id, u8 is_add)
+{
+ nat64_main_t *nm = &nat64_main;
+ snat_address_t *a = 0;
+ snat_interface_t *interface;
+ int i;
+
+ /* Check if address already exists */
+ for (i = 0; i < vec_len (nm->addr_pool); i++)
+ {
+ if (nm->addr_pool[i].addr.as_u32 == addr->as_u32)
+ {
+ a = nm->addr_pool + i;
+ break;
+ }
+ }
+
+ if (is_add)
+ {
+ if (a)
+ return VNET_API_ERROR_VALUE_EXIST;
+
+ vec_add2 (nm->addr_pool, a, 1);
+ a->addr = *addr;
+ a->fib_index = 0;
+ if (vrf_id != ~0)
+ a->fib_index =
+ fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP6, vrf_id);
+#define _(N, i, n, s) \
+ clib_bitmap_alloc (a->busy_##n##_port_bitmap, 65535);
+ foreach_snat_protocol
+#undef _
+ }
+ else
+ {
+ if (!a)
+ return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+ if (a->fib_index)
+ fib_table_unlock (a->fib_index, FIB_PROTOCOL_IP6);
+
+#define _(N, id, n, s) \
+ clib_bitmap_free (a->busy_##n##_port_bitmap);
+ foreach_snat_protocol
+#undef _
+ /* Delete sessions using address */
+ nat64_db_free_out_addr (&nm->db, &a->addr);
+ vec_del1 (nm->addr_pool, i);
+ }
+
+ /* Add/del external address to FIB */
+ /* *INDENT-OFF* */
+ pool_foreach (interface, nm->interfaces,
+ ({
+ if (interface->is_inside)
+ continue;
+
+ snat_add_del_addr_to_fib (addr, 32, interface->sw_if_index, is_add);
+ break;
+ }));
+ /* *INDENT-ON* */
+
+ return 0;
+}
+
+void
+nat64_pool_addr_walk (nat64_pool_addr_walk_fn_t fn, void *ctx)
+{
+ nat64_main_t *nm = &nat64_main;
+ snat_address_t *a = 0;
+
+ /* *INDENT-OFF* */
+ vec_foreach (a, nm->addr_pool)
+ {
+ if (fn (a, ctx))
+ break;
+ };
+ /* *INDENT-ON* */
+}
+
+int
+nat64_add_del_interface (u32 sw_if_index, u8 is_inside, u8 is_add)
+{
+ nat64_main_t *nm = &nat64_main;
+ snat_interface_t *interface = 0, *i;
+ snat_address_t *ap;
+ const char *feature_name, *arc_name;
+
+ /* Check if address already exists */
+ /* *INDENT-OFF* */
+ pool_foreach (i, nm->interfaces,
+ ({
+ if (i->sw_if_index == sw_if_index)
+ {
+ interface = i;
+ break;
+ }
+ }));
+ /* *INDENT-ON* */
+
+ if (is_add)
+ {
+ if (interface)
+ return VNET_API_ERROR_VALUE_EXIST;
+
+ pool_get (nm->interfaces, interface);
+ interface->sw_if_index = sw_if_index;
+ interface->is_inside = is_inside;
+
+ }
+ else
+ {
+ if (!interface)
+ return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+ pool_put (nm->interfaces, interface);
+ }
+
+ if (!is_inside)
+ {
+ /* *INDENT-OFF* */
+ vec_foreach (ap, nm->addr_pool)
+ snat_add_del_addr_to_fib(&ap->addr, 32, sw_if_index, is_add);
+ /* *INDENT-ON* */
+ }
+
+ arc_name = is_inside ? "ip6-unicast" : "ip4-unicast";
+ feature_name = is_inside ? "nat64-in2out" : "nat64-out2in";
+
+ return vnet_feature_enable_disable (arc_name, feature_name, sw_if_index,
+ is_add, 0, 0);
+}
+
+void
+nat64_interfaces_walk (nat64_interface_walk_fn_t fn, void *ctx)
+{
+ nat64_main_t *nm = &nat64_main;
+ snat_interface_t *i = 0;
+
+ /* *INDENT-OFF* */
+ pool_foreach (i, nm->interfaces,
+ ({
+ if (fn (i, ctx))
+ break;
+ }));
+ /* *INDENT-ON* */
+}
+
+int
+nat64_alloc_out_addr_and_port (u32 fib_index, snat_protocol_t proto,
+ ip4_address_t * addr, u16 * port)
+{
+ nat64_main_t *nm = &nat64_main;
+ snat_main_t *sm = &snat_main;
+ int i;
+ snat_address_t *a, *ga = 0;
+ u32 portnum;
+
+ for (i = 0; i < vec_len (nm->addr_pool); i++)
+ {
+ a = nm->addr_pool + i;
+ switch (proto)
+ {
+#define _(N, j, n, s) \
+ case SNAT_PROTOCOL_##N: \
+ if (a->busy_##n##_ports < (65535-1024)) \
+ { \
+ if (a->fib_index == fib_index) \
+ { \
+ while (1) \
+ { \
+ portnum = random_u32 (&sm->random_seed); \
+ portnum &= 0xFFFF; \
+ if (portnum < 1024) \
+ continue; \
+ if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
+ portnum)) \
+ continue; \
+ clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, \
+ portnum, 1); \
+ a->busy_##n##_ports++; \
+ *port = portnum; \
+ addr->as_u32 = a->addr.as_u32; \
+ return 0; \
+ } \
+ } \
+ else if (a->fib_index == 0) \
+ ga = a; \
+ } \
+ break;
+ foreach_snat_protocol
+#undef _
+ default:
+ clib_warning ("unknown protocol");
+ return 1;
+ }
+ }
+
+ if (ga)
+ {
+ switch (proto)
+ {
+#define _(N, j, n, s) \
+ case SNAT_PROTOCOL_##N: \
+ while (1) \
+ { \
+ portnum = random_u32 (&sm->random_seed); \
+ portnum &= 0xFFFF; \
+ if (portnum < 1024) \
+ continue; \
+ if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
+ portnum)) \
+ continue; \
+ clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, \
+ portnum, 1); \
+ a->busy_##n##_ports++; \
+ *port = portnum; \
+ addr->as_u32 = a->addr.as_u32; \
+ return 0; \
+ }
+ break;
+ foreach_snat_protocol
+#undef _
+ default:
+ clib_warning ("unknown protocol");
+ return 1;
+ }
+ }
+
+ /* Totally out of translations to use... */
+ //TODO: IPFix
+ return 1;
+}
+
+void
+nat64_free_out_addr_and_port (ip4_address_t * addr, u16 port,
+ snat_protocol_t proto)
+{
+ nat64_main_t *nm = &nat64_main;
+ int i;
+ snat_address_t *a;
+
+ for (i = 0; i < vec_len (nm->addr_pool); i++)
+ {
+ a = nm->addr_pool + i;
+ if (addr->as_u32 != a->addr.as_u32)
+ continue;
+ switch (proto)
+ {
+#define _(N, j, n, s) \
+ case SNAT_PROTOCOL_##N: \
+ ASSERT (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
+ port) == 1); \
+ clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, port, 0); \
+ a->busy_##n##_ports--; \
+ break;
+ foreach_snat_protocol
+#undef _
+ default:
+ clib_warning ("unknown protocol");
+ return;
+ }
+ break;
+ }
+}
+
+int
+nat64_add_del_static_bib_entry (ip6_address_t * in_addr,
+ ip4_address_t * out_addr, u16 in_port,
+ u16 out_port, u8 proto, u32 vrf_id, u8 is_add)
+{
+ nat64_main_t *nm = &nat64_main;
+ nat64_db_bib_entry_t *bibe;
+ u32 fib_index =
+ fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP6, vrf_id);
+ snat_protocol_t p = ip_proto_to_snat_proto (proto);
+ ip46_address_t addr;
+ int i;
+ snat_address_t *a;
+
+ addr.as_u64[0] = in_addr->as_u64[0];
+ addr.as_u64[1] = in_addr->as_u64[1];
+ bibe =
+ nat64_db_bib_entry_find (&nm->db, &addr, clib_host_to_net_u16 (in_port),
+ proto, fib_index, 1);
+
+ if (is_add)
+ {
+ if (bibe)
+ return VNET_API_ERROR_VALUE_EXIST;
+
+ for (i = 0; i < vec_len (nm->addr_pool); i++)
+ {
+ a = nm->addr_pool + i;
+ if (out_addr->as_u32 != a->addr.as_u32)
+ continue;
+ switch (p)
+ {
+#define _(N, j, n, s) \
+ case SNAT_PROTOCOL_##N: \
+ if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
+ out_port)) \
+ return VNET_API_ERROR_INVALID_VALUE; \
+ clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, \
+ out_port, 1); \
+ if (out_port > 1024) \
+ a->busy_##n##_ports++; \
+ break;
+ foreach_snat_protocol
+#undef _
+ default:
+ memset (&addr, 0, sizeof (addr));
+ addr.ip4.as_u32 = out_addr->as_u32;
+ if (nat64_db_bib_entry_find
+ (&nm->db, &addr, 0, proto, fib_index, 0))
+ return VNET_API_ERROR_INVALID_VALUE;
+ }
+ break;
+ }
+ bibe =
+ nat64_db_bib_entry_create (&nm->db, in_addr, out_addr,
+ clib_host_to_net_u16 (in_port),
+ clib_host_to_net_u16 (out_port), fib_index,
+ proto, 1);
+ if (!bibe)
+ return VNET_API_ERROR_UNSPECIFIED;
+ }
+ else
+ {
+ if (!bibe)
+ return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+ nat64_free_out_addr_and_port (out_addr, out_port, p);
+ nat64_db_bib_entry_free (&nm->db, bibe);
+ }
+
+ return 0;
+}
+
+int
+nat64_set_udp_timeout (u32 timeout)
+{
+ nat64_main_t *nm = &nat64_main;
+
+ if (timeout == 0)
+ nm->udp_timeout = SNAT_UDP_TIMEOUT;
+ else if (timeout < SNAT_UDP_TIMEOUT_MIN)
+ return VNET_API_ERROR_INVALID_VALUE;
+ else
+ nm->udp_timeout = timeout;
+
+ return 0;
+}
+
+u32
+nat64_get_udp_timeout (void)
+{
+ nat64_main_t *nm = &nat64_main;
+
+ return nm->udp_timeout;
+}
+
+int
+nat64_set_icmp_timeout (u32 timeout)
+{
+ nat64_main_t *nm = &nat64_main;
+
+ if (timeout == 0)
+ nm->icmp_timeout = SNAT_ICMP_TIMEOUT;
+ else
+ nm->icmp_timeout = timeout;
+
+ return 0;
+}
+
+u32
+nat64_get_icmp_timeout (void)
+{
+ nat64_main_t *nm = &nat64_main;
+
+ return nm->icmp_timeout;
+}
+
+int
+nat64_set_tcp_timeouts (u32 trans, u32 est, u32 incoming_syn)
+{
+ nat64_main_t *nm = &nat64_main;
+
+ if (trans == 0)
+ nm->tcp_trans_timeout = SNAT_TCP_TRANSITORY_TIMEOUT;
+ else
+ nm->tcp_trans_timeout = trans;
+
+ if (est == 0)
+ nm->tcp_est_timeout = SNAT_TCP_ESTABLISHED_TIMEOUT;
+ else
+ nm->tcp_est_timeout = est;
+
+ if (incoming_syn == 0)
+ nm->tcp_incoming_syn_timeout = SNAT_TCP_INCOMING_SYN;
+ else
+ nm->tcp_incoming_syn_timeout = incoming_syn;
+
+ return 0;
+}
+
+u32
+nat64_get_tcp_trans_timeout (void)
+{
+ nat64_main_t *nm = &nat64_main;
+
+ return nm->tcp_trans_timeout;
+}
+
+u32
+nat64_get_tcp_est_timeout (void)
+{
+ nat64_main_t *nm = &nat64_main;
+
+ return nm->tcp_est_timeout;
+}
+
+u32
+nat64_get_tcp_incoming_syn_timeout (void)
+{
+ nat64_main_t *nm = &nat64_main;
+
+ return nm->tcp_incoming_syn_timeout;
+}
+
+void
+nat64_session_reset_timeout (nat64_db_st_entry_t * ste, vlib_main_t * vm)
+{
+ nat64_main_t *nm = &nat64_main;
+ u32 now = (u32) vlib_time_now (vm);
+
+ switch (ip_proto_to_snat_proto (ste->proto))
+ {
+ case SNAT_PROTOCOL_ICMP:
+ ste->expire = now + nm->icmp_timeout;
+ return;
+ case SNAT_PROTOCOL_TCP:
+ {
+ switch (ste->tcp_state)
+ {
+ case NAT64_TCP_STATE_V4_INIT:
+ case NAT64_TCP_STATE_V6_INIT:
+ case NAT64_TCP_STATE_V4_FIN_RCV:
+ case NAT64_TCP_STATE_V6_FIN_RCV:
+ case NAT64_TCP_STATE_V6_FIN_V4_FIN_RCV:
+ case NAT64_TCP_STATE_TRANS:
+ ste->expire = now + nm->tcp_trans_timeout;
+ return;
+ case NAT64_TCP_STATE_ESTABLISHED:
+ ste->expire = now + nm->tcp_est_timeout;
+ return;
+ default:
+ return;
+ }
+ }
+ case SNAT_PROTOCOL_UDP:
+ ste->expire = now + nm->udp_timeout;
+ return;
+ default:
+ ste->expire = now + nm->udp_timeout;
+ return;
+ }
+}
+
+void
+nat64_tcp_session_set_state (nat64_db_st_entry_t * ste, tcp_header_t * tcp,
+ u8 is_ip6)
+{
+ switch (ste->tcp_state)
+ {
+ case NAT64_TCP_STATE_CLOSED:
+ {
+ if (tcp->flags & TCP_FLAG_SYN)
+ {
+ if (is_ip6)
+ ste->tcp_state = NAT64_TCP_STATE_V6_INIT;
+ else
+ ste->tcp_state = NAT64_TCP_STATE_V4_INIT;
+ }
+ return;
+ }
+ case NAT64_TCP_STATE_V4_INIT:
+ {
+ if (is_ip6 && (tcp->flags & TCP_FLAG_SYN))
+ ste->tcp_state = NAT64_TCP_STATE_ESTABLISHED;
+ return;
+ }
+ case NAT64_TCP_STATE_V6_INIT:
+ {
+ if (!is_ip6 && (tcp->flags & TCP_FLAG_SYN))
+ ste->tcp_state = NAT64_TCP_STATE_ESTABLISHED;
+ return;
+ }
+ case NAT64_TCP_STATE_ESTABLISHED:
+ {
+ if (tcp->flags & TCP_FLAG_FIN)
+ {
+ if (is_ip6)
+ ste->tcp_state = NAT64_TCP_STATE_V6_FIN_RCV;
+ else
+ ste->tcp_state = NAT64_TCP_STATE_V4_FIN_RCV;
+ }
+ else if (tcp->flags & TCP_FLAG_RST)
+ {
+ ste->tcp_state = NAT64_TCP_STATE_TRANS;
+ }
+ return;
+ }
+ case NAT64_TCP_STATE_V4_FIN_RCV:
+ {
+ if (is_ip6 && (tcp->flags & TCP_FLAG_FIN))
+ ste->tcp_state = NAT64_TCP_STATE_V6_FIN_V4_FIN_RCV;
+ return;
+ }
+ case NAT64_TCP_STATE_V6_FIN_RCV:
+ {
+ if (!is_ip6 && (tcp->flags & TCP_FLAG_FIN))
+ ste->tcp_state = NAT64_TCP_STATE_V6_FIN_V4_FIN_RCV;
+ return;
+ }
+ case NAT64_TCP_STATE_TRANS:
+ {
+ if (!(tcp->flags & TCP_FLAG_RST))
+ ste->tcp_state = NAT64_TCP_STATE_ESTABLISHED;
+ return;
+ }
+ default:
+ return;
+ }
+}
+
+int
+nat64_add_del_prefix (ip6_address_t * prefix, u8 plen, u32 vrf_id, u8 is_add)
+{
+ nat64_main_t *nm = &nat64_main;
+ nat64_prefix_t *p = 0;
+ int i;
+
+ /* Verify prefix length */
+ if (plen != 32 && plen != 40 && plen != 48 && plen != 56 && plen != 64
+ && plen != 96)
+ return VNET_API_ERROR_INVALID_VALUE;
+
+ /* Check if tenant already have prefix */
+ for (i = 0; i < vec_len (nm->pref64); i++)
+ {
+ if (nm->pref64[i].vrf_id == vrf_id)
+ {
+ p = nm->pref64 + i;
+ break;
+ }
+ }
+
+ if (is_add)
+ {
+ if (!p)
+ {
+ vec_add2 (nm->pref64, p, 1);
+ p->fib_index =
+ fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP6, vrf_id);
+ p->vrf_id = vrf_id;
+ }
+
+ p->prefix.as_u64[0] = prefix->as_u64[0];
+ p->prefix.as_u64[1] = prefix->as_u64[1];
+ p->plen = plen;
+ }
+ else
+ {
+ if (!p)
+ return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+ vec_del1 (nm->pref64, i);
+ }
+
+ return 0;
+}
+
+void
+nat64_prefix_walk (nat64_prefix_walk_fn_t fn, void *ctx)
+{
+ nat64_main_t *nm = &nat64_main;
+ nat64_prefix_t *p = 0;
+
+ /* *INDENT-OFF* */
+ vec_foreach (p, nm->pref64)
+ {
+ if (fn (p, ctx))
+ break;
+ };
+ /* *INDENT-ON* */
+}
+
+void
+nat64_compose_ip6 (ip6_address_t * ip6, ip4_address_t * ip4, u32 fib_index)
+{
+ nat64_main_t *nm = &nat64_main;
+ nat64_prefix_t *p, *gp = 0, *prefix = 0;
+
+ /* *INDENT-OFF* */
+ vec_foreach (p, nm->pref64)
+ {
+ if (p->fib_index == fib_index)
+ {
+ prefix = p;
+ break;
+ }
+
+ if (p->fib_index == 0)
+ gp = p;
+ };
+ /* *INDENT-ON* */
+
+ if (!prefix)
+ prefix = gp;
+
+ if (prefix)
+ {
+ memset (ip6, 0, 16);
+ memcpy (ip6, &p->prefix, p->plen);
+ switch (p->plen)
+ {
+ case 32:
+ ip6->as_u32[1] = ip4->as_u32;
+ break;
+ case 40:
+ ip6->as_u8[5] = ip4->as_u8[0];
+ ip6->as_u8[6] = ip4->as_u8[1];
+ ip6->as_u8[7] = ip4->as_u8[2];
+ ip6->as_u8[9] = ip4->as_u8[3];
+ break;
+ case 48:
+ ip6->as_u8[6] = ip4->as_u8[0];
+ ip6->as_u8[7] = ip4->as_u8[1];
+ ip6->as_u8[9] = ip4->as_u8[2];
+ ip6->as_u8[10] = ip4->as_u8[3];
+ break;
+ case 56:
+ ip6->as_u8[7] = ip4->as_u8[0];
+ ip6->as_u8[9] = ip4->as_u8[1];
+ ip6->as_u8[10] = ip4->as_u8[2];
+ ip6->as_u8[11] = ip4->as_u8[3];
+ break;
+ case 64:
+ ip6->as_u8[9] = ip4->as_u8[0];
+ ip6->as_u8[10] = ip4->as_u8[1];
+ ip6->as_u8[11] = ip4->as_u8[2];
+ ip6->as_u8[12] = ip4->as_u8[3];
+ break;
+ case 96:
+ ip6->as_u32[3] = ip4->as_u32;
+ break;
+ default:
+ clib_warning ("invalid prefix length");
+ break;
+ }
+ }
+ else
+ {
+ memcpy (ip6, well_known_prefix, 16);
+ ip6->as_u32[3] = ip4->as_u32;
+ }
+}
+
+void
+nat64_extract_ip4 (ip6_address_t * ip6, ip4_address_t * ip4, u32 fib_index)
+{
+ nat64_main_t *nm = &nat64_main;
+ nat64_prefix_t *p, *gp = 0;
+ u8 plen = 0;
+
+ /* *INDENT-OFF* */
+ vec_foreach (p, nm->pref64)
+ {
+ if (p->fib_index == fib_index)
+ {
+ plen = p->plen;
+ break;
+ }
+
+ if (p->vrf_id == 0)
+ gp = p;
+ };
+ /* *INDENT-ON* */
+
+ if (!plen)
+ {
+ if (gp)
+ plen = gp->plen;
+ else
+ plen = 96;
+ }
+
+ switch (plen)
+ {
+ case 32:
+ ip4->as_u32 = ip6->as_u32[1];
+ break;
+ case 40:
+ ip4->as_u8[0] = ip6->as_u8[5];
+ ip4->as_u8[1] = ip6->as_u8[6];
+ ip4->as_u8[2] = ip6->as_u8[7];
+ ip4->as_u8[3] = ip6->as_u8[9];
+ break;
+ case 48:
+ ip4->as_u8[0] = ip6->as_u8[6];
+ ip4->as_u8[1] = ip6->as_u8[7];
+ ip4->as_u8[2] = ip6->as_u8[9];
+ ip4->as_u8[3] = ip6->as_u8[10];
+ break;
+ case 56:
+ ip4->as_u8[0] = ip6->as_u8[7];
+ ip4->as_u8[1] = ip6->as_u8[9];
+ ip4->as_u8[2] = ip6->as_u8[10];
+ ip4->as_u8[3] = ip6->as_u8[11];
+ break;
+ case 64:
+ ip4->as_u8[0] = ip6->as_u8[9];
+ ip4->as_u8[1] = ip6->as_u8[10];
+ ip4->as_u8[2] = ip6->as_u8[11];
+ ip4->as_u8[3] = ip6->as_u8[12];
+ break;
+ case 96:
+ ip4->as_u32 = ip6->as_u32[3];
+ break;
+ default:
+ clib_warning ("invalid prefix length");
+ break;
+ }
+}
+
+/**
+ * @brief The 'nat64-expire-walk' process's main loop.
+ *
+ * Check expire time for NAT64 sessions.
+ */
+static uword
+nat64_expire_walk_fn (vlib_main_t * vm, vlib_node_runtime_t * rt,
+ vlib_frame_t * f)
+{
+ nat64_main_t *nm = &nat64_main;
+
+ while (!nm->is_disabled)
+ {
+ vlib_process_wait_for_event_or_clock (vm, 10.0);
+ vlib_process_get_events (vm, NULL);
+ u32 now = (u32) vlib_time_now (vm);
+
+ nad64_db_st_free_expired (&nm->db, now);
+ }
+
+ return 0;
+}
+
+static vlib_node_registration_t nat64_expire_walk_node;
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat64_expire_walk_node, static) = {
+ .function = nat64_expire_walk_fn,
+ .type = VLIB_NODE_TYPE_PROCESS,
+ .name = "nat64-expire-walk",
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */