/* * nat.h - NAT plugin definitions * * Copyright (c) 2016 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. */ #ifndef __included_nat_h__ #define __included_nat_h__ #include #include #include #include #include #include #include #include #include #include #define SNAT_UDP_TIMEOUT 300 #define SNAT_UDP_TIMEOUT_MIN 120 #define SNAT_TCP_TRANSITORY_TIMEOUT 240 #define SNAT_TCP_ESTABLISHED_TIMEOUT 7440 #define SNAT_TCP_INCOMING_SYN 6 #define SNAT_ICMP_TIMEOUT 60 #define SNAT_FLAG_HAIRPINNING (1 << 0) /* Key */ typedef struct { union { struct { ip4_address_t addr; u16 port; u16 protocol:3, fib_index:13; }; u64 as_u64; }; } snat_session_key_t; typedef struct { union { struct { ip4_address_t l_addr; ip4_address_t r_addr; u32 proto:8, fib_index:24; u16 l_port; u16 r_port; }; u64 as_u64[2]; }; } nat_ed_ses_key_t; typedef struct { union { struct { ip4_address_t ext_host_addr; u16 ext_host_port; u16 out_port; }; u64 as_u64; }; } snat_det_out_key_t; typedef struct { union { struct { ip4_address_t addr; u32 fib_index; }; u64 as_u64; }; } snat_user_key_t; #define foreach_snat_protocol \ _(UDP, 0, udp, "udp") \ _(TCP, 1, tcp, "tcp") \ _(ICMP, 2, icmp, "icmp") typedef enum { #define _(N, i, n, s) SNAT_PROTOCOL_##N = i, foreach_snat_protocol #undef _ } snat_protocol_t; #define foreach_snat_session_state \ _(0, UNKNOWN, "unknown") \ _(1, UDP_ACTIVE, "udp-active") \ _(2, TCP_SYN_SENT, "tcp-syn-sent") \ _(3, TCP_ESTABLISHED, "tcp-established") \ _(4, TCP_FIN_WAIT, "tcp-fin-wait") \ _(5, TCP_CLOSE_WAIT, "tcp-close-wait") \ _(6, TCP_LAST_ACK, "tcp-last-ack") \ _(7, ICMP_ACTIVE, "icmp-active") typedef enum { #define _(v, N, s) SNAT_SESSION_##N = v, foreach_snat_session_state #undef _ } snat_session_state_t; #define SNAT_SESSION_FLAG_STATIC_MAPPING 1 #define SNAT_SESSION_FLAG_UNKNOWN_PROTO 2 #define SNAT_SESSION_FLAG_LOAD_BALANCING 4 #define SNAT_SESSION_FLAG_TWICE_NAT 8 #define NAT_INTERFACE_FLAG_IS_INSIDE 1 #define NAT_INTERFACE_FLAG_IS_OUTSIDE 2 typedef CLIB_PACKED(struct { snat_session_key_t out2in; /* 0-15 */ snat_session_key_t in2out; /* 16-31 */ u32 flags; /* 32-35 */ /* per-user translations */ u32 per_user_index; /* 36-39 */ u32 per_user_list_head_index; /* 40-43 */ /* Last heard timer */ f64 last_heard; /* 44-51 */ u64 total_bytes; /* 52-59 */ u32 total_pkts; /* 60-63 */ /* Outside address */ u32 outside_address_index; /* 64-67 */ /* External host address and port */ ip4_address_t ext_host_addr; /* 68-71 */ u16 ext_host_port; /* 72-73 */ /* External hos address and port after translation */ ip4_address_t ext_host_nat_addr; /* 74-77 */ u16 ext_host_nat_port; /* 78-79 */ }) snat_session_t; typedef struct { ip4_address_t addr; u32 fib_index; u32 sessions_per_user_list_head_index; u32 nsessions; u32 nstaticsessions; } snat_user_t; typedef struct { ip4_address_t addr; u32 fib_index; #define _(N, i, n, s) \ u16 busy_##n##_ports; \ u16 * busy_##n##_ports_per_thread; \ uword * busy_##n##_port_bitmap; foreach_snat_protocol #undef _ } snat_address_t; typedef struct { u16 in_port; snat_det_out_key_t out; u8 state; u32 expire; } snat_det_session_t; typedef struct { ip4_address_t in_addr; u8 in_plen; ip4_address_t out_addr; u8 out_plen; u32 sharing_ratio; u16 ports_per_host; u32 ses_num; /* vector of sessions */ snat_det_session_t * sessions; } snat_det_map_t; typedef struct { ip4_address_t addr; u16 port; u8 probability; u8 prefix; } nat44_lb_addr_port_t; typedef struct { ip4_address_t local_addr; ip4_address_t external_addr; u16 local_port; u16 external_port; u8 addr_only; u8 twice_nat; u8 out2in_only; u32 vrf_id; u32 fib_index; snat_protocol_t proto; u32 worker_index; u8 *tag; nat44_lb_addr_port_t *locals; } snat_static_mapping_t; typedef struct { u32 sw_if_index; u8 flags; } snat_interface_t; typedef struct { ip4_address_t l_addr; u16 l_port; u16 e_port; u32 sw_if_index; u32 vrf_id; snat_protocol_t proto; int addr_only; int twice_nat; int is_add; u8 *tag; } snat_static_map_resolve_t; typedef struct { /* Main lookup tables */ clib_bihash_8_8_t out2in; clib_bihash_8_8_t in2out; /* Find-a-user => src address lookup */ clib_bihash_8_8_t user_hash; /* User pool */ snat_user_t * users; /* Session pool */ snat_session_t * sessions; /* Pool of doubly-linked list elements */ dlist_elt_t * list_pool; u32 snat_thread_index; } snat_main_per_thread_data_t; struct snat_main_s; typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm, vlib_node_runtime_t *node, u32 thread_index, vlib_buffer_t *b0, ip4_header_t *ip0, u8 *p_proto, snat_session_key_t *p_value, u8 *p_dont_translate, void *d, void *e); typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index); typedef int nat_alloc_out_addr_and_port_function_t (snat_address_t * addresses, u32 fib_index, u32 thread_index, snat_session_key_t * k, u32 * address_indexp, u16 port_per_thread, u32 snat_thread_index); typedef struct snat_main_s { /* Endpoint address dependent sessions lookup tables */ clib_bihash_16_8_t out2in_ed; clib_bihash_16_8_t in2out_ed; snat_icmp_match_function_t * icmp_match_in2out_cb; snat_icmp_match_function_t * icmp_match_out2in_cb; u32 num_workers; u32 first_worker_index; u32 next_worker; u32 * workers; snat_get_worker_function_t * worker_in2out_cb; snat_get_worker_function_t * worker_out2in_cb; u16 port_per_thread; u32 num_snat_thread; /* Per thread data */ snat_main_per_thread_data_t * per_thread_data; /* Find a static mapping by local */ clib_bihash_8_8_t static_mapping_by_local; /* Find a static mapping by external */ clib_bihash_8_8_t static_mapping_by_external; /* Static mapping pool */ snat_static_mapping_t * static_mappings; /* Interface pool */ snat_interface_t * interfaces; snat_interface_t * output_feature_interfaces; /* Vector of outside addresses */ snat_address_t * addresses; nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port; u8 psid_offset; u8 psid_length; u16 psid; /* Vector of twice NAT addresses for extenal hosts */ snat_address_t * twice_nat_addresses; /* sw_if_indices whose intfc addresses should be auto-added */ u32 * auto_add_sw_if_indices; u32 * auto_add_sw_if_indices_twice_nat; /* vector of interface address static mappings to resolve. */ snat_static_map_resolve_t *to_resolve; /* Randomize port allocation order */ u32 random_seed; /* Worker handoff index */ u32 fq_in2out_index; u32 fq_in2out_output_index; u32 fq_out2in_index; /* in2out and out2in node index */ u32 in2out_node_index; u32 in2out_output_node_index; u32 out2in_node_index; /* Deterministic NAT */ snat_det_map_t * det_maps; /* If forwarding is enabled */ u8 forwarding_enabled; /* Config parameters */ u8 static_mapping_only; u8 static_mapping_connection_tracking; u8 deterministic; u8 out2in_dpo; u32 translation_buckets; u32 translation_memory_size; u32 max_translations; u32 user_buckets; u32 user_memory_size; u32 max_translations_per_user; u32 outside_vrf_id; u32 outside_fib_index; u32 inside_vrf_id; u32 inside_fib_index; /* values of various timeouts */ u32 udp_timeout; u32 tcp_established_timeout; u32 tcp_transitory_timeout; u32 icmp_timeout; /* API message ID base */ u16 msg_id_base; /* convenience */ vlib_main_t * vlib_main; vnet_main_t * vnet_main; ip4_main_t * ip4_main; ip_lookup_main_t * ip4_lookup_main; api_main_t * api_main; } snat_main_t; extern snat_main_t snat_main; extern vlib_node_registration_t snat_in2out_node; extern vlib_node_registration_t snat_in2out_output_node; extern vlib_node_registration_t snat_out2in_node; extern vlib_node_registration_t snat_in2out_fast_node; extern vlib_node_registration_t snat_out2in_fast_node; extern vlib_node_registration_t snat_in2out_worker_handoff_node; extern vlib_node_registration_t snat_in2out_output_worker_handoff_node; extern vlib_node_registration_t snat_out2in_worker_handoff_node; extern vlib_node_registration_t snat_det_in2out_node; extern vlib_node_registration_t snat_det_out2in_node; extern vlib_node_registration_t snat_hairpin_dst_node; extern vlib_node_registration_t snat_hairpin_src_node; void snat_free_outside_address_and_port (snat_address_t * addresses, u32 thread_index, snat_session_key_t * k, u32 address_index); int snat_alloc_outside_address_and_port (snat_address_t * addresses, u32 fib_index, u32 thread_index, snat_session_key_t * k, u32 * address_indexp, u16 port_per_thread, u32 snat_thread_index); int snat_static_mapping_match (snat_main_t * sm, snat_session_key_t match, snat_session_key_t * mapping, u8 by_external, u8 *is_addr_only, u8 *twice_nat, u8 *lb); void snat_add_del_addr_to_fib (ip4_address_t * addr, u8 p_len, u32 sw_if_index, int is_add); format_function_t format_snat_user; format_function_t format_snat_static_mapping; format_function_t format_snat_static_map_to_resolve; format_function_t format_det_map_ses; typedef struct { u32 cached_sw_if_index; u32 cached_ip4_address; } snat_runtime_t; /** \brief Check if SNAT session is created from static mapping. @param s SNAT session @return 1 if SNAT session is created from static mapping otherwise 0 */ #define snat_is_session_static(s) (s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING) /** \brief Check if SNAT session for unknown protocol. @param s SNAT session @return 1 if SNAT session for unknown protocol otherwise 0 */ #define snat_is_unk_proto_session(s) (s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO) /** \brief Check if NAT session is twice NAT. @param s NAT session @return 1 if NAT session is twice NAT */ #define is_twice_nat_session(s) (s->flags & SNAT_SESSION_FLAG_TWICE_NAT) /** \brief Check if NAT session is load-balancing. @param s NAT session @return 1 if NAT session is load-balancing */ #define is_lb_session(s) (s->flags & SNAT_SESSION_FLAG_LOAD_BALANCING) /** \brief Check if NAT session is endpoint dependent. @param s NAT session @return 1 if NAT session is endpoint dependent */ #define is_ed_session(s) (snat_is_unk_proto_session (s) || is_twice_nat_session (s) || is_lb_session (s)) #define nat_interface_is_inside(i) i->flags & NAT_INTERFACE_FLAG_IS_INSIDE #define nat_interface_is_outside(i) i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE /* * Why is this here? Because we don't need to touch this layer to * simply reply to an icmp. We need to change id to a unique * value to NAT an echo request/reply. */ typedef struct { u16 identifier; u16 sequence; } icmp_echo_header_t; always_inline u32 ip_proto_to_snat_proto (u8 ip_proto) { u32 snat_proto = ~0; snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto; snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto; snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto; snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto; return snat_proto; } always_inline u8 snat_proto_to_ip_proto (snat_protocol_t snat_proto) { u8 ip_proto = ~0; ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto; ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto; ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto; return ip_proto; } typedef struct { u16 src_port, dst_port; } tcp_udp_header_t; u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node, u32 thread_index, vlib_buffer_t *b0, ip4_header_t *ip0, u8 *p_proto, snat_session_key_t *p_value, u8 *p_dont_translate, void *d, void *e); u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node, u32 thread_index, vlib_buffer_t *b0, ip4_header_t *ip0, u8 *p_proto, snat_session_key_t *p_value, u8 *p_dont_translate, void *d, void *e); u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node, u32 thread_index, vlib_buffer_t *b0, ip4_header_t *ip0, u8 *p_proto, snat_session_key_t *p_value, u8 *p_dont_translate, void *d, void *e); u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node, u32 thread_index, vlib_buffer_t *b0, ip4_header_t *ip0, u8 *p_proto, snat_session_key_t *p_value, u8 *p_dont_translate, void *d, void *e); u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node, u32 thread_index, vlib_buffer_t *b0, ip4_header_t *ip0, u8 *p_proto, snat_session_key_t *p_value, u8 *p_dont_translate, void *d, void *e); u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node, u32 thread_index, vlib_buffer_t *b0, ip4_header_t *ip0, u8 *p_proto, snat_session_key_t *p_value, u8 *p_dont_translate, void *d, void *e); void increment_v4_address(ip4_address_t * a); void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id, u8 twice_nat); int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm, u8 twice_nat); void nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add); int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr, u16 l_port, u16 e_port, u32 vrf_id, int addr_only, u32 sw_if_index, snat_protocol_t proto, int is_add, u8 twice_nat, u8 out2in_only, u8 *tag); clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm); int snat_set_workers (uword * bitmap); int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del); int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside, int is_del); int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del, u8 twice_nat); uword unformat_snat_protocol(unformat_input_t * input, va_list * args); u8 * format_snat_protocol(u8 * s, va_list * args); int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port, snat_protocol_t proto, u32 vrf_id, nat44_lb_addr_port_t *locals, u8 is_add, u8 twice_nat, u8 out2in_only, u8 *tag); int nat44_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port, snat_protocol_t proto, u32 vrf_id, int is_in); void nat_free_session_data (snat_main_t * sm, snat_session_t * s, u32 thread_index); snat_user_t * nat_user_get_or_create (snat_main_t *sm, ip4_address_t *addr, u32 fib_index, u32 thread_index); snat_session_t * nat_session_alloc_or_recycle (snat_main_t *sm, snat_user_t *u, u32 thread_index); void nat_set_alloc_addr_and_port_mape (u16 psid, u16 psid_offset, u16 psid_length); void nat_set_alloc_addr_and_port_default (void); static_always_inline u8 icmp_is_error_message (icmp46_header_t * icmp) { switch(icmp->type) { case ICMP4_destination_unreachable: case ICMP4_time_exceeded: case ICMP4_parameter_problem: case ICMP4_source_quench: case ICMP4_redirect: case ICMP4_alternate_host_address: return 1; } return 0; } static_always_inline u8 is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0, u32 ip4_addr) { snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data; ip4_address_t * first_int_addr; if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0)) { first_int_addr = ip4_interface_first_address (sm->ip4_main, sw_if_index0, 0 /* just want the address */); rt->cached_sw_if_index = sw_if_index0; if (first_int_addr) rt->cached_ip4_address = first_int_addr->as_u32; else rt->cached_ip4_address = 0; } if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address)) return 1; else return 0; } always_inline u8 maximum_sessions_exceeded (snat_main_t *sm, u32 thread_index) { if (pool_elts (sm->per_thread_data[thread_index].sessions) >= sm->max_translations) return 1; return 0; } static_always_inline void nat_send_all_to_node(vlib_main_t *vm, u32 *bi_vector, vlib_node_runtime_t *node, vlib_error_t *error, u32 next) { u32 n_left_from, *from, next_index, *to_next, n_left_to_next; from = bi_vector; n_left_from = vec_len(bi_vector); next_index = node->cached_next_index; while (n_left_from > 0) { vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next); while (n_left_from > 0 && n_left_to_next > 0) { u32 bi0 = to_next[0] = from[0]; from += 1; n_left_from -= 1; to_next += 1; n_left_to_next -= 1; vlib_buffer_t *p0 = vlib_get_buffer(vm, bi0); p0->error = *error; vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next, n_left_to_next, bi0, next); } vlib_put_next_frame(vm, node, next_index, n_left_to_next); } } always_inline void user_session_increment(snat_main_t *sm, snat_user_t *u, u8 is_static) { if (u->nsessions + u->nstaticsessions < sm->max_translations_per_user) { if (is_static) u->nstaticsessions++; else u->nsessions++; } } #endif /* __included_snat_h__ */