3 * nat.h - NAT plugin definitions
5 * Copyright (c) 2016 Cisco and/or its affiliates.
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at:
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
18 #ifndef __included_nat_h__
19 #define __included_nat_h__
21 #include <vnet/vnet.h>
22 #include <vnet/ip/ip.h>
23 #include <vnet/ethernet/ethernet.h>
24 #include <vnet/ip/icmp46_packet.h>
25 #include <vnet/api_errno.h>
26 #include <vppinfra/bihash_8_8.h>
27 #include <vppinfra/bihash_16_8.h>
28 #include <vppinfra/dlist.h>
29 #include <vppinfra/error.h>
30 #include <vlibapi/api.h>
33 #define SNAT_UDP_TIMEOUT 300
34 #define SNAT_UDP_TIMEOUT_MIN 120
35 #define SNAT_TCP_TRANSITORY_TIMEOUT 240
36 #define SNAT_TCP_ESTABLISHED_TIMEOUT 7440
37 #define SNAT_TCP_INCOMING_SYN 6
38 #define SNAT_ICMP_TIMEOUT 60
40 #define SNAT_FLAG_HAIRPINNING (1 << 0)
78 ip4_address_t ext_host_addr;
99 #define foreach_snat_protocol \
100 _(UDP, 0, udp, "udp") \
101 _(TCP, 1, tcp, "tcp") \
102 _(ICMP, 2, icmp, "icmp")
105 #define _(N, i, n, s) SNAT_PROTOCOL_##N = i,
106 foreach_snat_protocol
111 #define foreach_snat_session_state \
112 _(0, UNKNOWN, "unknown") \
113 _(1, UDP_ACTIVE, "udp-active") \
114 _(2, TCP_SYN_SENT, "tcp-syn-sent") \
115 _(3, TCP_ESTABLISHED, "tcp-established") \
116 _(4, TCP_FIN_WAIT, "tcp-fin-wait") \
117 _(5, TCP_CLOSE_WAIT, "tcp-close-wait") \
118 _(6, TCP_CLOSING, "tcp-closing") \
119 _(7, TCP_LAST_ACK, "tcp-last-ack") \
120 _(8, TCP_CLOSED, "tcp-closed") \
121 _(9, ICMP_ACTIVE, "icmp-active")
124 #define _(v, N, s) SNAT_SESSION_##N = v,
125 foreach_snat_session_state
127 } snat_session_state_t;
130 #define SNAT_SESSION_FLAG_STATIC_MAPPING 1
131 #define SNAT_SESSION_FLAG_UNKNOWN_PROTO 2
132 #define SNAT_SESSION_FLAG_LOAD_BALANCING 4
133 #define SNAT_SESSION_FLAG_TWICE_NAT 8
134 #define SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT 16
135 #define SNAT_SESSION_FLAG_FWD_BYPASS 32
137 #define NAT_INTERFACE_FLAG_IS_INSIDE 1
138 #define NAT_INTERFACE_FLAG_IS_OUTSIDE 2
140 typedef CLIB_PACKED(struct {
141 snat_session_key_t out2in; /* 0-15 */
143 snat_session_key_t in2out; /* 16-31 */
145 u32 flags; /* 32-35 */
147 /* per-user translations */
148 u32 per_user_index; /* 36-39 */
150 u32 per_user_list_head_index; /* 40-43 */
152 /* Last heard timer */
153 f64 last_heard; /* 44-51 */
155 u64 total_bytes; /* 52-59 */
157 u32 total_pkts; /* 60-63 */
159 /* Outside address */
160 u32 outside_address_index; /* 64-67 */
162 /* External host address and port */
163 ip4_address_t ext_host_addr; /* 68-71 */
164 u16 ext_host_port; /* 72-73 */
166 /* External hos address and port after translation */
167 ip4_address_t ext_host_nat_addr; /* 74-77 */
168 u16 ext_host_nat_port; /* 78-79 */
170 /* TCP session state */
178 u32 sessions_per_user_list_head_index;
186 #define _(N, i, n, s) \
187 u16 busy_##n##_ports; \
188 u16 * busy_##n##_ports_per_thread; \
189 uword * busy_##n##_port_bitmap;
190 foreach_snat_protocol
196 snat_det_out_key_t out;
199 } snat_det_session_t;
202 ip4_address_t in_addr;
204 ip4_address_t out_addr;
209 /* vector of sessions */
210 snat_det_session_t * sessions;
218 } nat44_lb_addr_port_t;
227 ip4_address_t local_addr;
228 ip4_address_t external_addr;
232 twice_nat_type_t twice_nat;
236 snat_protocol_t proto;
239 nat44_lb_addr_port_t *locals;
240 } snat_static_mapping_t;
248 ip4_address_t l_addr;
253 snat_protocol_t proto;
258 } snat_static_map_resolve_t;
261 /* Main lookup tables */
262 clib_bihash_8_8_t out2in;
263 clib_bihash_8_8_t in2out;
265 /* Find-a-user => src address lookup */
266 clib_bihash_8_8_t user_hash;
272 snat_session_t * sessions;
274 /* Pool of doubly-linked list elements */
275 dlist_elt_t * list_pool;
277 u32 snat_thread_index;
278 } snat_main_per_thread_data_t;
282 typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
283 vlib_node_runtime_t *node,
288 snat_session_key_t *p_value,
289 u8 *p_dont_translate,
293 typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);
295 typedef int nat_alloc_out_addr_and_port_function_t (snat_address_t * addresses,
298 snat_session_key_t * k,
299 u32 * address_indexp,
301 u32 snat_thread_index);
303 typedef struct snat_main_s {
304 /* Endpoint address dependent sessions lookup tables */
305 clib_bihash_16_8_t out2in_ed;
306 clib_bihash_16_8_t in2out_ed;
308 snat_icmp_match_function_t * icmp_match_in2out_cb;
309 snat_icmp_match_function_t * icmp_match_out2in_cb;
312 u32 first_worker_index;
315 snat_get_worker_function_t * worker_in2out_cb;
316 snat_get_worker_function_t * worker_out2in_cb;
320 /* Per thread data */
321 snat_main_per_thread_data_t * per_thread_data;
323 /* Find a static mapping by local */
324 clib_bihash_8_8_t static_mapping_by_local;
326 /* Find a static mapping by external */
327 clib_bihash_8_8_t static_mapping_by_external;
329 /* Static mapping pool */
330 snat_static_mapping_t * static_mappings;
333 snat_interface_t * interfaces;
334 snat_interface_t * output_feature_interfaces;
336 /* Vector of outside addresses */
337 snat_address_t * addresses;
338 nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port;
343 /* Vector of twice NAT addresses for extenal hosts */
344 snat_address_t * twice_nat_addresses;
346 /* sw_if_indices whose intfc addresses should be auto-added */
347 u32 * auto_add_sw_if_indices;
348 u32 * auto_add_sw_if_indices_twice_nat;
350 /* vector of interface address static mappings to resolve. */
351 snat_static_map_resolve_t *to_resolve;
353 /* Randomize port allocation order */
356 /* Worker handoff index */
358 u32 fq_in2out_output_index;
361 /* in2out and out2in node index */
362 u32 in2out_node_index;
363 u32 in2out_output_node_index;
364 u32 out2in_node_index;
366 /* Deterministic NAT */
367 snat_det_map_t * det_maps;
369 /* If forwarding is enabled */
370 u8 forwarding_enabled;
372 /* Config parameters */
373 u8 static_mapping_only;
374 u8 static_mapping_connection_tracking;
377 u32 translation_buckets;
378 u32 translation_memory_size;
379 u32 max_translations;
381 u32 user_memory_size;
382 u32 max_translations_per_user;
384 u32 outside_fib_index;
386 u32 inside_fib_index;
388 /* values of various timeouts */
390 u32 tcp_established_timeout;
391 u32 tcp_transitory_timeout;
394 /* API message ID base */
398 vlib_main_t * vlib_main;
399 vnet_main_t * vnet_main;
400 ip4_main_t * ip4_main;
401 ip_lookup_main_t * ip4_lookup_main;
402 api_main_t * api_main;
405 extern snat_main_t snat_main;
406 extern vlib_node_registration_t snat_in2out_node;
407 extern vlib_node_registration_t snat_in2out_output_node;
408 extern vlib_node_registration_t snat_out2in_node;
409 extern vlib_node_registration_t snat_in2out_fast_node;
410 extern vlib_node_registration_t snat_out2in_fast_node;
411 extern vlib_node_registration_t snat_in2out_worker_handoff_node;
412 extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
413 extern vlib_node_registration_t snat_out2in_worker_handoff_node;
414 extern vlib_node_registration_t snat_det_in2out_node;
415 extern vlib_node_registration_t snat_det_out2in_node;
416 extern vlib_node_registration_t snat_hairpin_dst_node;
417 extern vlib_node_registration_t snat_hairpin_src_node;
419 void snat_free_outside_address_and_port (snat_address_t * addresses,
421 snat_session_key_t * k,
424 int snat_alloc_outside_address_and_port (snat_address_t * addresses,
427 snat_session_key_t * k,
428 u32 * address_indexp,
430 u32 snat_thread_index);
432 int snat_static_mapping_match (snat_main_t * sm,
433 snat_session_key_t match,
434 snat_session_key_t * mapping,
437 twice_nat_type_t *twice_nat,
440 void snat_add_del_addr_to_fib (ip4_address_t * addr,
445 format_function_t format_snat_user;
446 format_function_t format_snat_static_mapping;
447 format_function_t format_snat_static_map_to_resolve;
448 format_function_t format_det_map_ses;
451 u32 cached_sw_if_index;
452 u32 cached_ip4_address;
455 /** \brief Check if SNAT session is created from static mapping.
456 @param s SNAT session
457 @return 1 if SNAT session is created from static mapping otherwise 0
459 #define snat_is_session_static(s) (s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING)
461 /** \brief Check if SNAT session for unknown protocol.
462 @param s SNAT session
463 @return 1 if SNAT session for unknown protocol otherwise 0
465 #define snat_is_unk_proto_session(s) (s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO)
467 /** \brief Check if NAT session is twice NAT.
469 @return 1 if NAT session is twice NAT
471 #define is_twice_nat_session(s) (s->flags & SNAT_SESSION_FLAG_TWICE_NAT)
473 /** \brief Check if NAT session is load-balancing.
475 @return 1 if NAT session is load-balancing
477 #define is_lb_session(s) (s->flags & SNAT_SESSION_FLAG_LOAD_BALANCING)
479 /** \brief Check if NAT session is forwarding bypass.
481 @return 1 if NAT session is load-balancing
483 #define is_fwd_bypass_session(s) (s->flags & SNAT_SESSION_FLAG_FWD_BYPASS)
485 /** \brief Check if NAT session is endpoint dependent.
487 @return 1 if NAT session is endpoint dependent
489 #define is_ed_session(s) (s->flags & SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT)
491 #define nat_interface_is_inside(i) i->flags & NAT_INTERFACE_FLAG_IS_INSIDE
492 #define nat_interface_is_outside(i) i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE
495 * Why is this here? Because we don't need to touch this layer to
496 * simply reply to an icmp. We need to change id to a unique
497 * value to NAT an echo request/reply.
503 } icmp_echo_header_t;
506 ip_proto_to_snat_proto (u8 ip_proto)
510 snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
511 snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
512 snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
513 snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
519 snat_proto_to_ip_proto (snat_protocol_t snat_proto)
523 ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
524 ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
525 ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
531 u16 src_port, dst_port;
534 u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
535 u32 thread_index, vlib_buffer_t *b0,
536 ip4_header_t *ip0, u8 *p_proto,
537 snat_session_key_t *p_value,
538 u8 *p_dont_translate, void *d, void *e);
539 u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
540 u32 thread_index, vlib_buffer_t *b0,
541 ip4_header_t *ip0, u8 *p_proto,
542 snat_session_key_t *p_value,
543 u8 *p_dont_translate, void *d, void *e);
544 u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
545 u32 thread_index, vlib_buffer_t *b0,
546 ip4_header_t *ip0, u8 *p_proto,
547 snat_session_key_t *p_value,
548 u8 *p_dont_translate, void *d, void *e);
549 u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
550 u32 thread_index, vlib_buffer_t *b0,
551 ip4_header_t *ip0, u8 *p_proto,
552 snat_session_key_t *p_value,
553 u8 *p_dont_translate, void *d, void *e);
554 u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
555 u32 thread_index, vlib_buffer_t *b0,
556 ip4_header_t *ip0, u8 *p_proto,
557 snat_session_key_t *p_value,
558 u8 *p_dont_translate, void *d, void *e);
559 u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node,
560 u32 thread_index, vlib_buffer_t *b0,
561 ip4_header_t *ip0, u8 *p_proto,
562 snat_session_key_t *p_value,
563 u8 *p_dont_translate, void *d, void *e);
564 void increment_v4_address(ip4_address_t * a);
565 void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id,
567 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm,
569 void nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add);
570 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
571 u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
572 u32 sw_if_index, snat_protocol_t proto, int is_add,
573 twice_nat_type_t twice_nat, u8 out2in_only,
575 clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
576 int snat_set_workers (uword * bitmap);
577 int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
578 int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside,
580 int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del,
582 uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
583 u8 * format_snat_protocol(u8 * s, va_list * args);
584 int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
585 snat_protocol_t proto, u32 vrf_id,
586 nat44_lb_addr_port_t *locals, u8 is_add,
587 twice_nat_type_t twice_nat, u8 out2in_only,
589 int nat44_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
590 snat_protocol_t proto, u32 vrf_id, int is_in);
591 void nat_free_session_data (snat_main_t * sm, snat_session_t * s,
593 snat_user_t * nat_user_get_or_create (snat_main_t *sm, ip4_address_t *addr,
594 u32 fib_index, u32 thread_index);
595 snat_session_t * nat_session_alloc_or_recycle (snat_main_t *sm, snat_user_t *u,
597 void nat_set_alloc_addr_and_port_mape (u16 psid, u16 psid_offset,
599 void nat_set_alloc_addr_and_port_default (void);
601 static_always_inline u8
602 icmp_is_error_message (icmp46_header_t * icmp)
606 case ICMP4_destination_unreachable:
607 case ICMP4_time_exceeded:
608 case ICMP4_parameter_problem:
609 case ICMP4_source_quench:
611 case ICMP4_alternate_host_address:
617 static_always_inline u8
618 is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
621 snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
622 ip4_address_t * first_int_addr;
624 if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
627 ip4_interface_first_address (sm->ip4_main, sw_if_index0,
628 0 /* just want the address */);
629 rt->cached_sw_if_index = sw_if_index0;
631 rt->cached_ip4_address = first_int_addr->as_u32;
633 rt->cached_ip4_address = 0;
636 if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
643 maximum_sessions_exceeded (snat_main_t *sm, u32 thread_index)
645 if (pool_elts (sm->per_thread_data[thread_index].sessions) >= sm->max_translations)
651 static_always_inline void
652 nat_send_all_to_node(vlib_main_t *vm, u32 *bi_vector,
653 vlib_node_runtime_t *node, vlib_error_t *error, u32 next)
655 u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
658 n_left_from = vec_len(bi_vector);
659 next_index = node->cached_next_index;
660 while (n_left_from > 0) {
661 vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next);
662 while (n_left_from > 0 && n_left_to_next > 0) {
663 u32 bi0 = to_next[0] = from[0];
668 vlib_buffer_t *p0 = vlib_get_buffer(vm, bi0);
670 vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next,
671 n_left_to_next, bi0, next);
673 vlib_put_next_frame(vm, node, next_index, n_left_to_next);
678 user_session_increment(snat_main_t *sm, snat_user_t *u, u8 is_static)
680 if (u->nsessions + u->nstaticsessions < sm->max_translations_per_user)
683 u->nstaticsessions++;
690 nat44_delete_session(snat_main_t * sm, snat_session_t * ses, u32 thread_index)
692 snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
694 clib_bihash_kv_8_8_t kv, value;
695 snat_user_key_t u_key;
697 u_key.addr = ses->in2out.addr;
698 u_key.fib_index = ses->in2out.fib_index;
699 kv.key = u_key.as_u64;
700 if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
702 u = pool_elt_at_index (tsm->users, value.value);
703 if (snat_is_session_static(ses))
704 u->nstaticsessions--;
708 clib_dlist_remove (tsm->list_pool, ses->per_user_index);
709 pool_put_index (tsm->list_pool, ses->per_user_index);
710 pool_put (tsm->sessions, ses);
713 /** \brief Set TCP session stet.
714 @return 1 if session was closed, otherwise 0
717 nat44_set_tcp_session_state(snat_main_t * sm, snat_session_t * ses,
718 tcp_header_t * tcp, u32 thread_index)
720 if (tcp->flags & TCP_FLAG_FIN && ses->state == SNAT_SESSION_UNKNOWN)
721 ses->state = SNAT_SESSION_TCP_FIN_WAIT;
722 else if (tcp->flags & TCP_FLAG_FIN && ses->state == SNAT_SESSION_TCP_FIN_WAIT)
723 ses->state = SNAT_SESSION_TCP_CLOSING;
724 else if (tcp->flags & TCP_FLAG_ACK && ses->state == SNAT_SESSION_TCP_FIN_WAIT)
725 ses->state = SNAT_SESSION_TCP_CLOSE_WAIT;
726 else if (tcp->flags & TCP_FLAG_FIN && ses->state == SNAT_SESSION_TCP_CLOSE_WAIT)
727 ses->state = SNAT_SESSION_TCP_LAST_ACK;
728 else if (tcp->flags & TCP_FLAG_ACK && ses->state == SNAT_SESSION_TCP_CLOSING)
729 ses->state = SNAT_SESSION_TCP_LAST_ACK;
730 else if (tcp->flags & TCP_FLAG_ACK && ses->state == SNAT_SESSION_TCP_LAST_ACK)
732 nat_free_session_data (sm, ses, thread_index);
733 ses->state = SNAT_SESSION_TCP_CLOSED;
734 nat44_delete_session (sm, ses, thread_index);
741 #endif /* __included_snat_h__ */