2 * det44.c - deterministic NAT
4 * Copyright (c) 2020 Cisco and/or its affiliates.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
19 * @brief deterministic NAT (CGN)
22 #include <vnet/vnet.h>
23 #include <vnet/ip/ip.h>
24 #include <vnet/ip/ip4.h>
25 #include <vpp/app/version.h>
26 #include <vnet/plugin/plugin.h>
28 #include <nat/det44/det44.h>
30 det44_main_t det44_main;
32 VNET_FEATURE_INIT (ip4_det44_in2out, static) = {
33 .arc_name = "ip4-unicast",
34 .node_name = "det44-in2out",
35 .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
36 "ip4-sv-reassembly-feature"),
38 VNET_FEATURE_INIT (ip4_det44_out2in, static) = {
39 .arc_name = "ip4-unicast",
40 .node_name = "det44-out2in",
41 .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
42 "ip4-sv-reassembly-feature",
43 "ip4-dhcp-client-detect"),
45 VLIB_PLUGIN_REGISTER () = {
46 .version = VPP_BUILD_VER,
47 .description = "Deterministic NAT (CGN)",
51 det44_add_del_addr_to_fib (ip4_address_t * addr, u8 p_len, u32 sw_if_index,
54 det44_main_t *dm = &det44_main;
55 fib_prefix_t prefix = {
57 .fp_proto = FIB_PROTOCOL_IP4,
59 .ip4.as_u32 = addr->as_u32,
62 u32 fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
66 fib_table_entry_update_one_path (fib_index,
69 (FIB_ENTRY_FLAG_CONNECTED |
70 FIB_ENTRY_FLAG_LOCAL |
71 FIB_ENTRY_FLAG_EXCLUSIVE),
75 ~0, 1, NULL, FIB_ROUTE_PATH_FLAG_NONE);
79 fib_table_entry_delete (fib_index, &prefix, dm->fib_src_low);
84 * @brief Add/delete deterministic NAT mapping.
86 * Create bijective mapping of inside address to outside address and port range
87 * pairs, with the purpose of enabling deterministic NAT to reduce logging in
90 * @param in_addr Inside network address.
91 * @param in_plen Inside network prefix length.
92 * @param out_addr Outside network address.
93 * @param out_plen Outside network prefix length.
94 * @param is_add If 0 delete, otherwise add.
97 snat_det_add_map (ip4_address_t * in_addr, u8 in_plen,
98 ip4_address_t * out_addr, u8 out_plen, int is_add)
100 static snat_det_session_t empty_snat_det_session = { 0 };
101 det44_main_t *dm = &det44_main;
102 ip4_address_t in_cmp, out_cmp;
103 det44_interface_t *i;
107 in_cmp.as_u32 = in_addr->as_u32 & ip4_main.fib_masks[in_plen];
108 out_cmp.as_u32 = out_addr->as_u32 & ip4_main.fib_masks[out_plen];
109 vec_foreach (mp, dm->det_maps)
111 /* Checking for overlapping addresses to be added here */
112 if (mp->in_addr.as_u32 == in_cmp.as_u32 &&
113 mp->in_plen == in_plen &&
114 mp->out_addr.as_u32 == out_cmp.as_u32 && mp->out_plen == out_plen)
121 /* If found, don't add again */
123 return VNET_API_ERROR_VALUE_EXIST;
125 /* If not found, don't delete */
126 if (!found && !is_add)
127 return VNET_API_ERROR_NO_SUCH_ENTRY;
131 pool_get (dm->det_maps, mp);
132 clib_memset (mp, 0, sizeof (*mp));
133 mp->in_addr.as_u32 = in_cmp.as_u32;
134 mp->in_plen = in_plen;
135 mp->out_addr.as_u32 = out_cmp.as_u32;
136 mp->out_plen = out_plen;
137 mp->sharing_ratio = (1 << (32 - in_plen)) / (1 << (32 - out_plen));
138 mp->ports_per_host = (65535 - 1023) / mp->sharing_ratio;
140 vec_validate_init_empty (mp->sessions,
141 DET44_SES_PER_USER * (1 << (32 - in_plen)) -
142 1, empty_snat_det_session);
146 vec_free (mp->sessions);
147 vec_del1 (dm->det_maps, mp - dm->det_maps);
150 /* Add/del external address range to FIB */
151 pool_foreach (i, dm->interfaces) {
152 if (det44_interface_is_inside(i))
154 det44_add_del_addr_to_fib(out_addr, out_plen, i->sw_if_index, is_add);
162 det44_set_timeouts (nat_timeouts_t * timeouts)
164 det44_main_t *dm = &det44_main;
166 dm->timeouts.udp = timeouts->udp;
167 if (timeouts->tcp.established)
168 dm->timeouts.tcp.established = timeouts->tcp.established;
169 if (timeouts->tcp.transitory)
170 dm->timeouts.tcp.transitory = timeouts->tcp.transitory;
172 dm->timeouts.icmp = timeouts->icmp;
177 det44_get_timeouts ()
179 det44_main_t *dm = &det44_main;
184 det44_reset_timeouts ()
186 det44_main_t *dm = &det44_main;
187 nat_reset_timeouts (&dm->timeouts);
191 det44_interface_add_del (u32 sw_if_index, u8 is_inside, int is_del)
193 det44_main_t *dm = &det44_main;
194 det44_interface_t *tmp, *i = 0;
195 const char *feature_name;
198 // TODO: if plugin is not enabled do not register nodes on interfaces
199 // rather make a structure and when enable call is used
200 // then register nodes
202 pool_foreach (tmp, dm->interfaces) {
203 if (tmp->sw_if_index == sw_if_index)
211 feature_name = is_inside ? "det44-in2out" : "det44-out2in";
217 det44_log_err ("det44 is not enabled on this interface");
218 return VNET_API_ERROR_INVALID_VALUE;
221 rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, 0);
225 rv = vnet_feature_enable_disable ("ip4-unicast", feature_name,
226 sw_if_index, 1, 0, 0);
230 pool_put (dm->interfaces, i);
236 det44_log_err ("det44 is already enabled on this interface");
237 return VNET_API_ERROR_INVALID_VALUE;
240 rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, 1);
244 rv = vnet_feature_enable_disable ("ip4-unicast", feature_name,
245 sw_if_index, 1, 0, 0);
249 pool_get (dm->interfaces, i);
250 clib_memset (i, 0, sizeof (*i));
252 i->sw_if_index = sw_if_index;
255 i->flags |= DET44_INTERFACE_FLAG_IS_INSIDE;
257 i->flags |= DET44_INTERFACE_FLAG_IS_OUTSIDE;
262 u32 fib_index = fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
264 // add/del outside interface fib to registry
266 det44_fib_t *outside_fib;
267 vec_foreach (outside_fib, dm->outside_fibs)
269 if (outside_fib->fib_index == fib_index)
273 outside_fib->refcount++;
277 outside_fib->refcount--;
278 if (!outside_fib->refcount)
280 vec_del1 (dm->outside_fibs,
281 outside_fib - dm->outside_fibs);
288 if (!is_del && !found)
290 vec_add2 (dm->outside_fibs, outside_fib, 1);
291 outside_fib->fib_index = fib_index;
292 outside_fib->refcount = 1;
294 // add/del outside address to FIB
296 pool_foreach (mp, dm->det_maps) {
297 det44_add_del_addr_to_fib(&mp->out_addr,
298 mp->out_plen, sw_if_index, !is_del);
305 * @brief The 'det44-expire-walk' process's main loop.
307 * Check expire time for active sessions.
310 det44_expire_walk_fn (vlib_main_t * vm, vlib_node_runtime_t * rt,
313 det44_main_t *dm = &det44_main;
314 snat_det_session_t *ses;
319 vlib_process_wait_for_event_or_clock (vm, 10.0);
320 vlib_process_get_events (vm, NULL);
321 u32 now = (u32) vlib_time_now (vm);
323 if (!plugin_enabled ())
328 pool_foreach (mp, dm->det_maps)
330 vec_foreach (ses, mp->sessions)
332 // close expired sessions
333 if (ses->in_port && (ses->expire < now))
335 snat_det_ses_close (mp, ses);
344 det44_create_expire_walk_process ()
346 det44_main_t *dm = &det44_main;
348 if (dm->expire_walk_node_index)
351 dm->expire_walk_node_index = vlib_process_create (vlib_get_main (),
353 det44_expire_walk_fn,
354 16 /* stack_bytes */ );
358 det44_plugin_enable (det44_config_t c)
360 det44_main_t *dm = &det44_main;
362 if (plugin_enabled () == 1)
364 det44_log_err ("plugin already enabled!");
368 det44_log_err ("inside %u, outside %u", c.inside_vrf_id, c.outside_vrf_id);
370 dm->outside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
373 dm->inside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
377 dm->mss_clamping = 0;
381 det44_create_expire_walk_process ();
386 det44_plugin_disable ()
388 det44_main_t *dm = &det44_main;
389 det44_interface_t *i, *interfaces;
393 if (plugin_enabled () == 0)
395 det44_log_err ("plugin already disabled!");
401 // DET44 cleanup (order dependent)
402 // 1) remove interfaces (det44_interface_add_del) removes map ranges from fib
406 interfaces = vec_dup (dm->interfaces);
407 vec_foreach (i, interfaces)
409 vnet_main_t *vnm = vnet_get_main ();
411 if (i->flags & DET44_INTERFACE_FLAG_IS_INSIDE)
413 rv = det44_interface_add_del (i->sw_if_index, i->flags, 1);
416 det44_log_err ("inside interface %U del failed",
417 unformat_vnet_sw_interface, vnm, i->sw_if_index);
421 if (i->flags & DET44_INTERFACE_FLAG_IS_OUTSIDE)
423 rv = det44_interface_add_del (i->sw_if_index, i->flags, 1);
426 det44_log_err ("outside interface %U del failed",
427 unformat_vnet_sw_interface, vnm, i->sw_if_index);
432 vec_free (interfaces);
434 pool_foreach (mp, dm->det_maps)
436 vec_free (mp->sessions);
439 det44_reset_timeouts ();
441 pool_free (dm->interfaces);
442 pool_free (dm->det_maps);
448 det44_update_outside_fib (ip4_main_t * im,
450 u32 sw_if_index, u32 new_fib_index,
453 det44_main_t *dm = &det44_main;
455 det44_fib_t *outside_fib;
456 det44_interface_t *i;
461 if (plugin_enabled () == 0)
464 if (new_fib_index == old_fib_index)
467 if (!vec_len (dm->outside_fibs))
470 pool_foreach (i, dm->interfaces)
472 if (i->sw_if_index == sw_if_index)
474 if (!(det44_interface_is_outside (i)))
483 vec_foreach (outside_fib, dm->outside_fibs)
485 if (outside_fib->fib_index == old_fib_index)
487 outside_fib->refcount--;
488 if (!outside_fib->refcount)
489 vec_del1 (dm->outside_fibs, outside_fib - dm->outside_fibs);
494 vec_foreach (outside_fib, dm->outside_fibs)
496 if (outside_fib->fib_index == new_fib_index)
498 outside_fib->refcount++;
506 vec_add2 (dm->outside_fibs, outside_fib, 1);
507 outside_fib->refcount = 1;
508 outside_fib->fib_index = new_fib_index;
512 static clib_error_t *
513 det44_init (vlib_main_t * vm)
515 det44_main_t *dm = &det44_main;
516 ip4_table_bind_callback_t cb;
519 clib_memset (dm, 0, sizeof (*dm));
521 dm->ip4_main = &ip4_main;
522 dm->log_class = vlib_log_register_class ("det44", 0);
524 node = vlib_get_node_by_name (vm, (u8 *) "det44-in2out");
525 dm->in2out_node_index = node->index;
526 node = vlib_get_node_by_name (vm, (u8 *) "det44-out2in");
527 dm->out2in_node_index = node->index;
529 dm->fib_src_hi = fib_source_allocate ("det44-hi",
530 FIB_SOURCE_PRIORITY_HI,
531 FIB_SOURCE_BH_SIMPLE);
532 dm->fib_src_low = fib_source_allocate ("det44-low",
533 FIB_SOURCE_PRIORITY_LOW,
534 FIB_SOURCE_BH_SIMPLE);
536 cb.function = det44_update_outside_fib;
537 cb.function_opaque = 0;
538 vec_add1 (dm->ip4_main->table_bind_callbacks, cb);
540 det44_reset_timeouts ();
541 return det44_api_hookup (vm);
544 VLIB_INIT_FUNCTION (det44_init);
547 format_det44_session_state (u8 * s, va_list * args)
549 u32 i = va_arg (*args, u32);
554 #define _(v, N, str) case DET44_SESSION_##N: t = (u8 *) str; break;
555 foreach_det44_session_state
558 t = format (t, "unknown");
560 s = format (s, "%s", t);
565 format_det_map_ses (u8 * s, va_list * args)
567 snat_det_map_t *det_map = va_arg (*args, snat_det_map_t *);
568 ip4_address_t in_addr, out_addr;
569 u32 in_offset, out_offset;
570 snat_det_session_t *ses = va_arg (*args, snat_det_session_t *);
571 u32 *i = va_arg (*args, u32 *);
573 u32 user_index = *i / DET44_SES_PER_USER;
575 clib_host_to_net_u32 (clib_net_to_host_u32 (det_map->in_addr.as_u32) +
578 clib_net_to_host_u32 (in_addr.as_u32) -
579 clib_net_to_host_u32 (det_map->in_addr.as_u32);
580 out_offset = in_offset / det_map->sharing_ratio;
582 clib_host_to_net_u32 (clib_net_to_host_u32 (det_map->out_addr.as_u32) +
586 "in %U:%d out %U:%d external host %U:%d state: %U expire: %d\n",
587 format_ip4_address, &in_addr, clib_net_to_host_u16 (ses->in_port),
588 format_ip4_address, &out_addr,
589 clib_net_to_host_u16 (ses->out.out_port), format_ip4_address,
590 &ses->out.ext_host_addr,
591 clib_net_to_host_u16 (ses->out.ext_host_port),
592 format_det44_session_state, ses->state, ses->expire);
598 * fd.io coding-style-patch-verification: ON
601 * eval: (c-set-style "gnu")