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;
129 #define NAT44_SES_I2O_FIN 1
130 #define NAT44_SES_O2I_FIN 2
131 #define NAT44_SES_I2O_FIN_ACK 4
132 #define NAT44_SES_O2I_FIN_ACK 8
134 #define nat44_is_ses_closed(s) (s->state == 0xf)
136 #define SNAT_SESSION_FLAG_STATIC_MAPPING 1
137 #define SNAT_SESSION_FLAG_UNKNOWN_PROTO 2
138 #define SNAT_SESSION_FLAG_LOAD_BALANCING 4
139 #define SNAT_SESSION_FLAG_TWICE_NAT 8
140 #define SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT 16
141 #define SNAT_SESSION_FLAG_FWD_BYPASS 32
143 #define NAT_INTERFACE_FLAG_IS_INSIDE 1
144 #define NAT_INTERFACE_FLAG_IS_OUTSIDE 2
146 typedef CLIB_PACKED(struct {
147 snat_session_key_t out2in; /* 0-15 */
149 snat_session_key_t in2out; /* 16-31 */
151 u32 flags; /* 32-35 */
153 /* per-user translations */
154 u32 per_user_index; /* 36-39 */
156 u32 per_user_list_head_index; /* 40-43 */
158 /* Last heard timer */
159 f64 last_heard; /* 44-51 */
161 u64 total_bytes; /* 52-59 */
163 u32 total_pkts; /* 60-63 */
165 /* Outside address */
166 u32 outside_address_index; /* 64-67 */
168 /* External host address and port */
169 ip4_address_t ext_host_addr; /* 68-71 */
170 u16 ext_host_port; /* 72-73 */
172 /* External hos address and port after translation */
173 ip4_address_t ext_host_nat_addr; /* 74-77 */
174 u16 ext_host_nat_port; /* 78-79 */
176 /* TCP session state */
186 u32 sessions_per_user_list_head_index;
194 #define _(N, i, n, s) \
195 u16 busy_##n##_ports; \
196 u16 * busy_##n##_ports_per_thread; \
197 uword * busy_##n##_port_bitmap;
198 foreach_snat_protocol
204 snat_det_out_key_t out;
207 } snat_det_session_t;
210 ip4_address_t in_addr;
212 ip4_address_t out_addr;
217 /* vector of sessions */
218 snat_det_session_t * sessions;
226 } nat44_lb_addr_port_t;
235 ip4_address_t local_addr;
236 ip4_address_t external_addr;
240 twice_nat_type_t twice_nat;
244 snat_protocol_t proto;
247 nat44_lb_addr_port_t *locals;
248 } snat_static_mapping_t;
256 ip4_address_t l_addr;
261 snat_protocol_t proto;
266 } snat_static_map_resolve_t;
269 /* Main lookup tables */
270 clib_bihash_8_8_t out2in;
271 clib_bihash_8_8_t in2out;
273 /* Find-a-user => src address lookup */
274 clib_bihash_8_8_t user_hash;
280 snat_session_t * sessions;
282 /* Pool of doubly-linked list elements */
283 dlist_elt_t * list_pool;
285 u32 snat_thread_index;
286 } snat_main_per_thread_data_t;
290 typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
291 vlib_node_runtime_t *node,
296 snat_session_key_t *p_value,
297 u8 *p_dont_translate,
301 typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);
303 typedef int nat_alloc_out_addr_and_port_function_t (snat_address_t * addresses,
306 snat_session_key_t * k,
307 u32 * address_indexp,
309 u32 snat_thread_index);
311 typedef struct snat_main_s {
312 /* Endpoint address dependent sessions lookup tables */
313 clib_bihash_16_8_t out2in_ed;
314 clib_bihash_16_8_t in2out_ed;
316 snat_icmp_match_function_t * icmp_match_in2out_cb;
317 snat_icmp_match_function_t * icmp_match_out2in_cb;
320 u32 first_worker_index;
323 snat_get_worker_function_t * worker_in2out_cb;
324 snat_get_worker_function_t * worker_out2in_cb;
328 /* Per thread data */
329 snat_main_per_thread_data_t * per_thread_data;
331 /* Find a static mapping by local */
332 clib_bihash_8_8_t static_mapping_by_local;
334 /* Find a static mapping by external */
335 clib_bihash_8_8_t static_mapping_by_external;
337 /* Static mapping pool */
338 snat_static_mapping_t * static_mappings;
341 snat_interface_t * interfaces;
342 snat_interface_t * output_feature_interfaces;
344 /* Vector of outside addresses */
345 snat_address_t * addresses;
346 nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port;
351 /* Vector of twice NAT addresses for extenal hosts */
352 snat_address_t * twice_nat_addresses;
354 /* sw_if_indices whose intfc addresses should be auto-added */
355 u32 * auto_add_sw_if_indices;
356 u32 * auto_add_sw_if_indices_twice_nat;
358 /* vector of interface address static mappings to resolve. */
359 snat_static_map_resolve_t *to_resolve;
361 /* Randomize port allocation order */
364 /* Worker handoff index */
366 u32 fq_in2out_output_index;
369 /* in2out and out2in node index */
370 u32 in2out_node_index;
371 u32 in2out_output_node_index;
372 u32 out2in_node_index;
374 /* Deterministic NAT */
375 snat_det_map_t * det_maps;
377 /* If forwarding is enabled */
378 u8 forwarding_enabled;
380 /* Config parameters */
381 u8 static_mapping_only;
382 u8 static_mapping_connection_tracking;
385 u32 translation_buckets;
386 u32 translation_memory_size;
387 u32 max_translations;
389 u32 user_memory_size;
390 u32 max_translations_per_user;
392 u32 outside_fib_index;
394 u32 inside_fib_index;
396 /* values of various timeouts */
398 u32 tcp_established_timeout;
399 u32 tcp_transitory_timeout;
402 /* API message ID base */
406 vlib_main_t * vlib_main;
407 vnet_main_t * vnet_main;
408 ip4_main_t * ip4_main;
409 ip_lookup_main_t * ip4_lookup_main;
410 api_main_t * api_main;
413 extern snat_main_t snat_main;
414 extern vlib_node_registration_t snat_in2out_node;
415 extern vlib_node_registration_t snat_in2out_output_node;
416 extern vlib_node_registration_t snat_out2in_node;
417 extern vlib_node_registration_t snat_in2out_fast_node;
418 extern vlib_node_registration_t snat_out2in_fast_node;
419 extern vlib_node_registration_t snat_in2out_worker_handoff_node;
420 extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
421 extern vlib_node_registration_t snat_out2in_worker_handoff_node;
422 extern vlib_node_registration_t snat_det_in2out_node;
423 extern vlib_node_registration_t snat_det_out2in_node;
424 extern vlib_node_registration_t snat_hairpin_dst_node;
425 extern vlib_node_registration_t snat_hairpin_src_node;
427 void snat_free_outside_address_and_port (snat_address_t * addresses,
429 snat_session_key_t * k,
432 int snat_alloc_outside_address_and_port (snat_address_t * addresses,
435 snat_session_key_t * k,
436 u32 * address_indexp,
438 u32 snat_thread_index);
440 int snat_static_mapping_match (snat_main_t * sm,
441 snat_session_key_t match,
442 snat_session_key_t * mapping,
445 twice_nat_type_t *twice_nat,
448 void snat_add_del_addr_to_fib (ip4_address_t * addr,
453 format_function_t format_snat_user;
454 format_function_t format_snat_static_mapping;
455 format_function_t format_snat_static_map_to_resolve;
456 format_function_t format_det_map_ses;
459 u32 cached_sw_if_index;
460 u32 cached_ip4_address;
463 /** \brief Check if SNAT session is created from static mapping.
464 @param s SNAT session
465 @return 1 if SNAT session is created from static mapping otherwise 0
467 #define snat_is_session_static(s) (s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING)
469 /** \brief Check if SNAT session for unknown protocol.
470 @param s SNAT session
471 @return 1 if SNAT session for unknown protocol otherwise 0
473 #define snat_is_unk_proto_session(s) (s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO)
475 /** \brief Check if NAT session is twice NAT.
477 @return 1 if NAT session is twice NAT
479 #define is_twice_nat_session(s) (s->flags & SNAT_SESSION_FLAG_TWICE_NAT)
481 /** \brief Check if NAT session is load-balancing.
483 @return 1 if NAT session is load-balancing
485 #define is_lb_session(s) (s->flags & SNAT_SESSION_FLAG_LOAD_BALANCING)
487 /** \brief Check if NAT session is forwarding bypass.
489 @return 1 if NAT session is load-balancing
491 #define is_fwd_bypass_session(s) (s->flags & SNAT_SESSION_FLAG_FWD_BYPASS)
493 /** \brief Check if NAT session is endpoint dependent.
495 @return 1 if NAT session is endpoint dependent
497 #define is_ed_session(s) (s->flags & SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT)
499 #define nat_interface_is_inside(i) i->flags & NAT_INTERFACE_FLAG_IS_INSIDE
500 #define nat_interface_is_outside(i) i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE
503 * Why is this here? Because we don't need to touch this layer to
504 * simply reply to an icmp. We need to change id to a unique
505 * value to NAT an echo request/reply.
511 } icmp_echo_header_t;
514 ip_proto_to_snat_proto (u8 ip_proto)
518 snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
519 snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
520 snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
521 snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
527 snat_proto_to_ip_proto (snat_protocol_t snat_proto)
531 ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
532 ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
533 ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
539 u16 src_port, dst_port;
542 u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
543 u32 thread_index, vlib_buffer_t *b0,
544 ip4_header_t *ip0, u8 *p_proto,
545 snat_session_key_t *p_value,
546 u8 *p_dont_translate, void *d, void *e);
547 u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
548 u32 thread_index, vlib_buffer_t *b0,
549 ip4_header_t *ip0, u8 *p_proto,
550 snat_session_key_t *p_value,
551 u8 *p_dont_translate, void *d, void *e);
552 u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
553 u32 thread_index, vlib_buffer_t *b0,
554 ip4_header_t *ip0, u8 *p_proto,
555 snat_session_key_t *p_value,
556 u8 *p_dont_translate, void *d, void *e);
557 u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
558 u32 thread_index, vlib_buffer_t *b0,
559 ip4_header_t *ip0, u8 *p_proto,
560 snat_session_key_t *p_value,
561 u8 *p_dont_translate, void *d, void *e);
562 u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
563 u32 thread_index, vlib_buffer_t *b0,
564 ip4_header_t *ip0, u8 *p_proto,
565 snat_session_key_t *p_value,
566 u8 *p_dont_translate, void *d, void *e);
567 u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node,
568 u32 thread_index, vlib_buffer_t *b0,
569 ip4_header_t *ip0, u8 *p_proto,
570 snat_session_key_t *p_value,
571 u8 *p_dont_translate, void *d, void *e);
572 void increment_v4_address(ip4_address_t * a);
573 void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id,
575 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm,
577 void nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add);
578 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
579 u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
580 u32 sw_if_index, snat_protocol_t proto, int is_add,
581 twice_nat_type_t twice_nat, u8 out2in_only,
583 clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
584 int snat_set_workers (uword * bitmap);
585 int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
586 int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside,
588 int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del,
590 uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
591 u8 * format_snat_protocol(u8 * s, va_list * args);
592 int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
593 snat_protocol_t proto, u32 vrf_id,
594 nat44_lb_addr_port_t *locals, u8 is_add,
595 twice_nat_type_t twice_nat, u8 out2in_only,
597 int nat44_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
598 snat_protocol_t proto, u32 vrf_id, int is_in);
599 int nat44_del_ed_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
600 ip4_address_t *eh_addr, u16 eh_port, u8 proto,
601 u32 vrf_id, int is_in);
602 void nat_free_session_data (snat_main_t * sm, snat_session_t * s,
604 snat_user_t * nat_user_get_or_create (snat_main_t *sm, ip4_address_t *addr,
605 u32 fib_index, u32 thread_index);
606 snat_session_t * nat_session_alloc_or_recycle (snat_main_t *sm, snat_user_t *u,
608 void nat_set_alloc_addr_and_port_mape (u16 psid, u16 psid_offset,
610 void nat_set_alloc_addr_and_port_default (void);
612 static_always_inline u8
613 icmp_is_error_message (icmp46_header_t * icmp)
617 case ICMP4_destination_unreachable:
618 case ICMP4_time_exceeded:
619 case ICMP4_parameter_problem:
620 case ICMP4_source_quench:
622 case ICMP4_alternate_host_address:
628 static_always_inline u8
629 is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
632 snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
633 ip4_address_t * first_int_addr;
635 if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
638 ip4_interface_first_address (sm->ip4_main, sw_if_index0,
639 0 /* just want the address */);
640 rt->cached_sw_if_index = sw_if_index0;
642 rt->cached_ip4_address = first_int_addr->as_u32;
644 rt->cached_ip4_address = 0;
647 if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
654 maximum_sessions_exceeded (snat_main_t *sm, u32 thread_index)
656 if (pool_elts (sm->per_thread_data[thread_index].sessions) >= sm->max_translations)
662 static_always_inline void
663 nat_send_all_to_node(vlib_main_t *vm, u32 *bi_vector,
664 vlib_node_runtime_t *node, vlib_error_t *error, u32 next)
666 u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
669 n_left_from = vec_len(bi_vector);
670 next_index = node->cached_next_index;
671 while (n_left_from > 0) {
672 vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next);
673 while (n_left_from > 0 && n_left_to_next > 0) {
674 u32 bi0 = to_next[0] = from[0];
679 vlib_buffer_t *p0 = vlib_get_buffer(vm, bi0);
681 vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next,
682 n_left_to_next, bi0, next);
684 vlib_put_next_frame(vm, node, next_index, n_left_to_next);
689 user_session_increment(snat_main_t *sm, snat_user_t *u, u8 is_static)
691 if (u->nsessions + u->nstaticsessions < sm->max_translations_per_user)
694 u->nstaticsessions++;
701 nat44_delete_session(snat_main_t * sm, snat_session_t * ses, u32 thread_index)
703 snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
705 clib_bihash_kv_8_8_t kv, value;
706 snat_user_key_t u_key;
708 u_key.addr = ses->in2out.addr;
709 u_key.fib_index = ses->in2out.fib_index;
710 kv.key = u_key.as_u64;
711 if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
713 u = pool_elt_at_index (tsm->users, value.value);
714 if (snat_is_session_static(ses))
715 u->nstaticsessions--;
719 clib_dlist_remove (tsm->list_pool, ses->per_user_index);
720 pool_put_index (tsm->list_pool, ses->per_user_index);
721 pool_put (tsm->sessions, ses);
724 /** \brief Set TCP session state.
725 @return 1 if session was closed, otherwise 0
728 nat44_set_tcp_session_state_i2o(snat_main_t * sm, snat_session_t * ses,
729 tcp_header_t * tcp, u32 thread_index)
731 if (tcp->flags & TCP_FLAG_FIN)
733 ses->i2o_fin_seq = clib_net_to_host_u32 (tcp->seq_number);
734 ses->state |= NAT44_SES_I2O_FIN;
736 if ((tcp->flags & TCP_FLAG_ACK) && (ses->state & NAT44_SES_O2I_FIN))
738 if (clib_net_to_host_u32 (tcp->ack_number) > ses->o2i_fin_seq)
739 ses->state |= NAT44_SES_O2I_FIN_ACK;
741 if (nat44_is_ses_closed (ses))
743 nat_free_session_data (sm, ses, thread_index);
744 nat44_delete_session (sm, ses, thread_index);
751 nat44_set_tcp_session_state_o2i(snat_main_t * sm, snat_session_t * ses,
752 tcp_header_t * tcp, u32 thread_index)
754 if (tcp->flags & TCP_FLAG_FIN)
756 ses->o2i_fin_seq = clib_net_to_host_u32 (tcp->seq_number);
757 ses->state |= NAT44_SES_O2I_FIN;
759 if ((tcp->flags & TCP_FLAG_ACK) && (ses->state & NAT44_SES_I2O_FIN))
761 if (clib_net_to_host_u32 (tcp->ack_number) > ses->i2o_fin_seq)
762 ses->state |= NAT44_SES_I2O_FIN_ACK;
764 if (nat44_is_ses_closed (ses))
766 nat_free_session_data (sm, ses, thread_index);
767 nat44_delete_session (sm, ses, thread_index);
773 #endif /* __included_snat_h__ */