diff options
Diffstat (limited to 'src/plugins/nat/nat_det_in2out.c')
| -rw-r--r-- | src/plugins/nat/nat_det_in2out.c | 884 |
1 files changed, 884 insertions, 0 deletions
diff --git a/src/plugins/nat/nat_det_in2out.c b/src/plugins/nat/nat_det_in2out.c new file mode 100644 index 00000000000..1366c2fce69 --- /dev/null +++ b/src/plugins/nat/nat_det_in2out.c @@ -0,0 +1,884 @@ +/* + * Copyright (c) 2018 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 Deterministic/CGN NAT44 inside to outside network translation + */ + +#include <vlib/vlib.h> +#include <vnet/vnet.h> +#include <vnet/ip/ip.h> +#include <vnet/fib/ip4_fib.h> +#include <vppinfra/error.h> +#include <vppinfra/elog.h> +#include <nat/nat.h> +#include <nat/nat_det.h> +#include <nat/nat_inlines.h> + +typedef struct +{ + u32 sw_if_index; + u32 next_index; + u32 session_index; +} nat_det_in2out_trace_t; + +typedef enum +{ + NAT_DET_IN2OUT_NEXT_LOOKUP, + NAT_DET_IN2OUT_NEXT_DROP, + NAT_DET_IN2OUT_NEXT_ICMP_ERROR, + NAT_DET_IN2OUT_N_NEXT, +} nat_det_in2out_next_t; + +#define foreach_nat_det_in2out_error \ +_(UNSUPPORTED_PROTOCOL, "Unsupported protocol") \ +_(NO_TRANSLATION, "No translation") \ +_(BAD_ICMP_TYPE, "unsupported ICMP type") \ +_(OUT_OF_PORTS, "Out of ports") \ +_(IN2OUT_PACKETS, "Good in2out packets processed") + +typedef enum +{ +#define _(sym,str) NAT_DET_IN2OUT_ERROR_##sym, + foreach_nat_det_in2out_error +#undef _ + NAT_DET_IN2OUT_N_ERROR, +} nat_det_in2out_error_t; + +static char *nat_det_in2out_error_strings[] = { +#define _(sym,string) string, + foreach_nat_det_in2out_error +#undef _ +}; + +vlib_node_registration_t snat_det_in2out_node; + +static u8 * +format_nat_det_in2out_trace (u8 * s, va_list * args) +{ + CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); + CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); + nat_det_in2out_trace_t *t = va_arg (*args, nat_det_in2out_trace_t *); + + s = format (s, "NAT_DET_IN2OUT: sw_if_index %d, next index %d, session %d", + t->sw_if_index, t->next_index, t->session_index); + + return s; +} + +/** + * Get address and port values to be used for ICMP packet translation + * and create session if needed + * + * @param[in,out] sm NAT main + * @param[in,out] node NAT node runtime + * @param[in] thread_index thread index + * @param[in,out] b0 buffer containing packet to be translated + * @param[out] p_proto protocol used for matching + * @param[out] p_value address and port after NAT translation + * @param[out] p_dont_translate if packet should not be translated + * @param d optional parameter + * @param e optional parameter + */ +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) +{ + icmp46_header_t *icmp0; + u32 sw_if_index0; + u32 rx_fib_index0; + u8 protocol; + snat_det_out_key_t key0; + u8 dont_translate = 0; + u32 next0 = ~0; + icmp_echo_header_t *echo0, *inner_echo0 = 0; + ip4_header_t *inner_ip0; + void *l4_header = 0; + icmp46_header_t *inner_icmp0; + snat_det_map_t *dm0 = 0; + ip4_address_t new_addr0; + u16 lo_port0, i0; + snat_det_session_t *ses0 = 0; + ip4_address_t in_addr; + u16 in_port; + + icmp0 = (icmp46_header_t *) ip4_next_header (ip0); + echo0 = (icmp_echo_header_t *) (icmp0 + 1); + sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX]; + rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0); + + if (!icmp_is_error_message (icmp0)) + { + protocol = SNAT_PROTOCOL_ICMP; + in_addr = ip0->src_address; + in_port = echo0->identifier; + } + else + { + inner_ip0 = (ip4_header_t *) (echo0 + 1); + l4_header = ip4_next_header (inner_ip0); + protocol = ip_proto_to_snat_proto (inner_ip0->protocol); + in_addr = inner_ip0->dst_address; + switch (protocol) + { + case SNAT_PROTOCOL_ICMP: + inner_icmp0 = (icmp46_header_t *) l4_header; + inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1); + in_port = inner_echo0->identifier; + break; + case SNAT_PROTOCOL_UDP: + case SNAT_PROTOCOL_TCP: + in_port = ((tcp_udp_header_t *) l4_header)->dst_port; + break; + default: + b0->error = node->errors[NAT_DET_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL]; + next0 = NAT_DET_IN2OUT_NEXT_DROP; + goto out; + } + } + + dm0 = snat_det_map_by_user (sm, &in_addr); + if (PREDICT_FALSE (!dm0)) + { + nat_log_info ("no match for internal host %U", + format_ip4_address, &in_addr); + if (PREDICT_FALSE (snat_not_translate_fast (sm, node, sw_if_index0, ip0, + IP_PROTOCOL_ICMP, + rx_fib_index0))) + { + dont_translate = 1; + goto out; + } + next0 = NAT_DET_IN2OUT_NEXT_DROP; + b0->error = node->errors[NAT_DET_IN2OUT_ERROR_NO_TRANSLATION]; + goto out; + } + + snat_det_forward (dm0, &in_addr, &new_addr0, &lo_port0); + + key0.ext_host_addr = ip0->dst_address; + key0.ext_host_port = 0; + + ses0 = snat_det_find_ses_by_in (dm0, &in_addr, in_port, key0); + if (PREDICT_FALSE (!ses0)) + { + if (PREDICT_FALSE (snat_not_translate_fast (sm, node, sw_if_index0, ip0, + IP_PROTOCOL_ICMP, + rx_fib_index0))) + { + dont_translate = 1; + goto out; + } + if (icmp0->type != ICMP4_echo_request) + { + b0->error = node->errors[NAT_DET_IN2OUT_ERROR_BAD_ICMP_TYPE]; + next0 = NAT_DET_IN2OUT_NEXT_DROP; + goto out; + } + for (i0 = 0; i0 < dm0->ports_per_host; i0++) + { + key0.out_port = clib_host_to_net_u16 (lo_port0 + + ((i0 + + clib_net_to_host_u16 + (echo0->identifier)) % + dm0->ports_per_host)); + + if (snat_det_get_ses_by_out (dm0, &in_addr, key0.as_u64)) + continue; + + ses0 = + snat_det_ses_create (dm0, &in_addr, echo0->identifier, &key0); + break; + } + if (PREDICT_FALSE (!ses0)) + { + next0 = NAT_DET_IN2OUT_NEXT_DROP; + b0->error = node->errors[NAT_DET_IN2OUT_ERROR_OUT_OF_PORTS]; + goto out; + } + } + + if (PREDICT_FALSE (icmp0->type != ICMP4_echo_request && + !icmp_is_error_message (icmp0))) + { + b0->error = node->errors[NAT_DET_IN2OUT_ERROR_BAD_ICMP_TYPE]; + next0 = NAT_DET_IN2OUT_NEXT_DROP; + goto out; + } + + u32 now = (u32) vlib_time_now (sm->vlib_main); + + ses0->state = SNAT_SESSION_ICMP_ACTIVE; + ses0->expire = now + sm->icmp_timeout; + +out: + *p_proto = protocol; + if (ses0) + { + p_value->addr = new_addr0; + p_value->fib_index = sm->outside_fib_index; + p_value->port = ses0->out.out_port; + } + *p_dont_translate = dont_translate; + if (d) + *(snat_det_session_t **) d = ses0; + if (e) + *(snat_det_map_t **) e = dm0; + return next0; +} + +static uword +snat_det_in2out_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * frame) +{ + u32 n_left_from, *from, *to_next; + nat_det_in2out_next_t next_index; + u32 pkts_processed = 0; + snat_main_t *sm = &snat_main; + u32 now = (u32) vlib_time_now (vm); + u32 thread_index = vm->thread_index; + + from = vlib_frame_vector_args (frame); + n_left_from = frame->n_vectors; + next_index = node->cached_next_index; + + while (n_left_from > 0) + { + u32 n_left_to_next; + + vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); + + while (n_left_from >= 4 && n_left_to_next >= 2) + { + u32 bi0, bi1; + vlib_buffer_t *b0, *b1; + u32 next0, next1; + u32 sw_if_index0, sw_if_index1; + ip4_header_t *ip0, *ip1; + ip_csum_t sum0, sum1; + ip4_address_t new_addr0, old_addr0, new_addr1, old_addr1; + u16 old_port0, new_port0, lo_port0, i0; + u16 old_port1, new_port1, lo_port1, i1; + udp_header_t *udp0, *udp1; + tcp_header_t *tcp0, *tcp1; + u32 proto0, proto1; + snat_det_out_key_t key0, key1; + snat_det_map_t *dm0, *dm1; + snat_det_session_t *ses0 = 0, *ses1 = 0; + u32 rx_fib_index0, rx_fib_index1; + icmp46_header_t *icmp0, *icmp1; + + /* Prefetch next iteration. */ + { + vlib_buffer_t *p2, *p3; + + p2 = vlib_get_buffer (vm, from[2]); + p3 = vlib_get_buffer (vm, from[3]); + + vlib_prefetch_buffer_header (p2, LOAD); + vlib_prefetch_buffer_header (p3, LOAD); + + CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE); + CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE); + } + + /* speculatively enqueue b0 and b1 to the current next frame */ + to_next[0] = bi0 = from[0]; + to_next[1] = bi1 = from[1]; + from += 2; + to_next += 2; + n_left_from -= 2; + n_left_to_next -= 2; + + b0 = vlib_get_buffer (vm, bi0); + b1 = vlib_get_buffer (vm, bi1); + + next0 = NAT_DET_IN2OUT_NEXT_LOOKUP; + next1 = NAT_DET_IN2OUT_NEXT_LOOKUP; + + ip0 = vlib_buffer_get_current (b0); + udp0 = ip4_next_header (ip0); + tcp0 = (tcp_header_t *) udp0; + + sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX]; + + if (PREDICT_FALSE (ip0->ttl == 1)) + { + vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; + icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded, + ICMP4_time_exceeded_ttl_exceeded_in_transit, + 0); + next0 = NAT_DET_IN2OUT_NEXT_ICMP_ERROR; + goto trace0; + } + + proto0 = ip_proto_to_snat_proto (ip0->protocol); + + if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP)) + { + rx_fib_index0 = + ip4_fib_table_get_index_for_sw_if_index (sw_if_index0); + icmp0 = (icmp46_header_t *) udp0; + + next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, + rx_fib_index0, node, next0, thread_index, + &ses0, &dm0); + goto trace0; + } + + dm0 = snat_det_map_by_user (sm, &ip0->src_address); + if (PREDICT_FALSE (!dm0)) + { + nat_log_info ("no match for internal host %U", + format_ip4_address, &ip0->src_address); + next0 = NAT_DET_IN2OUT_NEXT_DROP; + b0->error = node->errors[NAT_DET_IN2OUT_ERROR_NO_TRANSLATION]; + goto trace0; + } + + snat_det_forward (dm0, &ip0->src_address, &new_addr0, &lo_port0); + + key0.ext_host_addr = ip0->dst_address; + key0.ext_host_port = tcp0->dst; + + ses0 = + snat_det_find_ses_by_in (dm0, &ip0->src_address, tcp0->src, key0); + if (PREDICT_FALSE (!ses0)) + { + for (i0 = 0; i0 < dm0->ports_per_host; i0++) + { + key0.out_port = clib_host_to_net_u16 (lo_port0 + + ((i0 + + clib_net_to_host_u16 + (tcp0->src)) % + dm0-> + ports_per_host)); + + if (snat_det_get_ses_by_out + (dm0, &ip0->src_address, key0.as_u64)) + continue; + + ses0 = + snat_det_ses_create (dm0, &ip0->src_address, tcp0->src, + &key0); + break; + } + if (PREDICT_FALSE (!ses0)) + { + /* too many sessions for user, send ICMP error packet */ + vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; + icmp4_error_set_vnet_buffer (b0, + ICMP4_destination_unreachable, + ICMP4_destination_unreachable_destination_unreachable_host, + 0); + next0 = NAT_DET_IN2OUT_NEXT_ICMP_ERROR; + goto trace0; + } + } + + new_port0 = ses0->out.out_port; + + old_addr0.as_u32 = ip0->src_address.as_u32; + ip0->src_address.as_u32 = new_addr0.as_u32; + vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm->outside_fib_index; + + sum0 = ip0->checksum; + sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32, + ip4_header_t, + src_address /* changed member */ ); + ip0->checksum = ip_csum_fold (sum0); + + if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP)) + { + if (tcp0->flags & TCP_FLAG_SYN) + ses0->state = SNAT_SESSION_TCP_SYN_SENT; + else if (tcp0->flags & TCP_FLAG_ACK + && ses0->state == SNAT_SESSION_TCP_SYN_SENT) + ses0->state = SNAT_SESSION_TCP_ESTABLISHED; + else if (tcp0->flags & TCP_FLAG_FIN + && ses0->state == SNAT_SESSION_TCP_ESTABLISHED) + ses0->state = SNAT_SESSION_TCP_FIN_WAIT; + else if (tcp0->flags & TCP_FLAG_ACK + && ses0->state == SNAT_SESSION_TCP_FIN_WAIT) + snat_det_ses_close (dm0, ses0); + else if (tcp0->flags & TCP_FLAG_FIN + && ses0->state == SNAT_SESSION_TCP_CLOSE_WAIT) + ses0->state = SNAT_SESSION_TCP_LAST_ACK; + else if (tcp0->flags == 0 + && ses0->state == SNAT_SESSION_UNKNOWN) + ses0->state = SNAT_SESSION_TCP_ESTABLISHED; + + old_port0 = tcp0->src; + tcp0->src = new_port0; + + sum0 = tcp0->checksum; + sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32, + ip4_header_t, + dst_address /* changed member */ ); + sum0 = ip_csum_update (sum0, old_port0, new_port0, + ip4_header_t /* cheat */ , + length /* changed member */ ); + mss_clamping (sm, tcp0, &sum0); + tcp0->checksum = ip_csum_fold (sum0); + } + else + { + ses0->state = SNAT_SESSION_UDP_ACTIVE; + old_port0 = udp0->src_port; + udp0->src_port = new_port0; + udp0->checksum = 0; + } + + switch (ses0->state) + { + case SNAT_SESSION_UDP_ACTIVE: + ses0->expire = now + sm->udp_timeout; + break; + case SNAT_SESSION_TCP_SYN_SENT: + case SNAT_SESSION_TCP_FIN_WAIT: + case SNAT_SESSION_TCP_CLOSE_WAIT: + case SNAT_SESSION_TCP_LAST_ACK: + ses0->expire = now + sm->tcp_transitory_timeout; + break; + case SNAT_SESSION_TCP_ESTABLISHED: + ses0->expire = now + sm->tcp_established_timeout; + break; + } + + trace0: + if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) + && (b0->flags & VLIB_BUFFER_IS_TRACED))) + { + nat_det_in2out_trace_t *t = + vlib_add_trace (vm, node, b0, sizeof (*t)); + t->sw_if_index = sw_if_index0; + t->next_index = next0; + t->session_index = ~0; + if (ses0) + t->session_index = ses0 - dm0->sessions; + } + + pkts_processed += next0 != NAT_DET_IN2OUT_NEXT_DROP; + + ip1 = vlib_buffer_get_current (b1); + udp1 = ip4_next_header (ip1); + tcp1 = (tcp_header_t *) udp1; + + sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX]; + + if (PREDICT_FALSE (ip1->ttl == 1)) + { + vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0; + icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded, + ICMP4_time_exceeded_ttl_exceeded_in_transit, + 0); + next1 = NAT_DET_IN2OUT_NEXT_ICMP_ERROR; + goto trace1; + } + + proto1 = ip_proto_to_snat_proto (ip1->protocol); + + if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP)) + { + rx_fib_index1 = + ip4_fib_table_get_index_for_sw_if_index (sw_if_index1); + icmp1 = (icmp46_header_t *) udp1; + + next1 = icmp_in2out (sm, b1, ip1, icmp1, sw_if_index1, + rx_fib_index1, node, next1, thread_index, + &ses1, &dm1); + goto trace1; + } + + dm1 = snat_det_map_by_user (sm, &ip1->src_address); + if (PREDICT_FALSE (!dm1)) + { + nat_log_info ("no match for internal host %U", + format_ip4_address, &ip0->src_address); + next1 = NAT_DET_IN2OUT_NEXT_DROP; + b1->error = node->errors[NAT_DET_IN2OUT_ERROR_NO_TRANSLATION]; + goto trace1; + } + + snat_det_forward (dm1, &ip1->src_address, &new_addr1, &lo_port1); + + key1.ext_host_addr = ip1->dst_address; + key1.ext_host_port = tcp1->dst; + + ses1 = + snat_det_find_ses_by_in (dm1, &ip1->src_address, tcp1->src, key1); + if (PREDICT_FALSE (!ses1)) + { + for (i1 = 0; i1 < dm1->ports_per_host; i1++) + { + key1.out_port = clib_host_to_net_u16 (lo_port1 + + ((i1 + + clib_net_to_host_u16 + (tcp1->src)) % + dm1-> + ports_per_host)); + + if (snat_det_get_ses_by_out + (dm1, &ip1->src_address, key1.as_u64)) + continue; + + ses1 = + snat_det_ses_create (dm1, &ip1->src_address, tcp1->src, + &key1); + break; + } + if (PREDICT_FALSE (!ses1)) + { + /* too many sessions for user, send ICMP error packet */ + vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0; + icmp4_error_set_vnet_buffer (b1, + ICMP4_destination_unreachable, + ICMP4_destination_unreachable_destination_unreachable_host, + 0); + next1 = NAT_DET_IN2OUT_NEXT_ICMP_ERROR; + goto trace1; + } + } + + new_port1 = ses1->out.out_port; + + old_addr1.as_u32 = ip1->src_address.as_u32; + ip1->src_address.as_u32 = new_addr1.as_u32; + vnet_buffer (b1)->sw_if_index[VLIB_TX] = sm->outside_fib_index; + + sum1 = ip1->checksum; + sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32, + ip4_header_t, + src_address /* changed member */ ); + ip1->checksum = ip_csum_fold (sum1); + + if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP)) + { + if (tcp1->flags & TCP_FLAG_SYN) + ses1->state = SNAT_SESSION_TCP_SYN_SENT; + else if (tcp1->flags & TCP_FLAG_ACK + && ses1->state == SNAT_SESSION_TCP_SYN_SENT) + ses1->state = SNAT_SESSION_TCP_ESTABLISHED; + else if (tcp1->flags & TCP_FLAG_FIN + && ses1->state == SNAT_SESSION_TCP_ESTABLISHED) + ses1->state = SNAT_SESSION_TCP_FIN_WAIT; + else if (tcp1->flags & TCP_FLAG_ACK + && ses1->state == SNAT_SESSION_TCP_FIN_WAIT) + snat_det_ses_close (dm1, ses1); + else if (tcp1->flags & TCP_FLAG_FIN + && ses1->state == SNAT_SESSION_TCP_CLOSE_WAIT) + ses1->state = SNAT_SESSION_TCP_LAST_ACK; + else if (tcp1->flags == 0 + && ses1->state == SNAT_SESSION_UNKNOWN) + ses1->state = SNAT_SESSION_TCP_ESTABLISHED; + + old_port1 = tcp1->src; + tcp1->src = new_port1; + + sum1 = tcp1->checksum; + sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32, + ip4_header_t, + dst_address /* changed member */ ); + sum1 = ip_csum_update (sum1, old_port1, new_port1, + ip4_header_t /* cheat */ , + length /* changed member */ ); + mss_clamping (sm, tcp1, &sum1); + tcp1->checksum = ip_csum_fold (sum1); + } + else + { + ses1->state = SNAT_SESSION_UDP_ACTIVE; + old_port1 = udp1->src_port; + udp1->src_port = new_port1; + udp1->checksum = 0; + } + + switch (ses1->state) + { + case SNAT_SESSION_UDP_ACTIVE: + ses1->expire = now + sm->udp_timeout; + break; + case SNAT_SESSION_TCP_SYN_SENT: + case SNAT_SESSION_TCP_FIN_WAIT: + case SNAT_SESSION_TCP_CLOSE_WAIT: + case SNAT_SESSION_TCP_LAST_ACK: + ses1->expire = now + sm->tcp_transitory_timeout; + break; + case SNAT_SESSION_TCP_ESTABLISHED: + ses1->expire = now + sm->tcp_established_timeout; + break; + } + + trace1: + if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) + && (b1->flags & VLIB_BUFFER_IS_TRACED))) + { + nat_det_in2out_trace_t *t = + vlib_add_trace (vm, node, b1, sizeof (*t)); + t->sw_if_index = sw_if_index1; + t->next_index = next1; + t->session_index = ~0; + if (ses1) + t->session_index = ses1 - dm1->sessions; + } + + pkts_processed += next1 != NAT_DET_IN2OUT_NEXT_DROP; + + /* verify speculative enqueues, maybe switch current next frame */ + vlib_validate_buffer_enqueue_x2 (vm, node, next_index, + to_next, n_left_to_next, + bi0, bi1, next0, next1); + } + + while (n_left_from > 0 && n_left_to_next > 0) + { + u32 bi0; + vlib_buffer_t *b0; + u32 next0; + u32 sw_if_index0; + ip4_header_t *ip0; + ip_csum_t sum0; + ip4_address_t new_addr0, old_addr0; + u16 old_port0, new_port0, lo_port0, i0; + udp_header_t *udp0; + tcp_header_t *tcp0; + u32 proto0; + snat_det_out_key_t key0; + snat_det_map_t *dm0; + snat_det_session_t *ses0 = 0; + u32 rx_fib_index0; + icmp46_header_t *icmp0; + + /* speculatively enqueue b0 to the current next frame */ + bi0 = from[0]; + to_next[0] = bi0; + from += 1; + to_next += 1; + n_left_from -= 1; + n_left_to_next -= 1; + + b0 = vlib_get_buffer (vm, bi0); + next0 = NAT_DET_IN2OUT_NEXT_LOOKUP; + + ip0 = vlib_buffer_get_current (b0); + udp0 = ip4_next_header (ip0); + tcp0 = (tcp_header_t *) udp0; + + sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX]; + + if (PREDICT_FALSE (ip0->ttl == 1)) + { + vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; + icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded, + ICMP4_time_exceeded_ttl_exceeded_in_transit, + 0); + next0 = NAT_DET_IN2OUT_NEXT_ICMP_ERROR; + goto trace00; + } + + proto0 = ip_proto_to_snat_proto (ip0->protocol); + + if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP)) + { + rx_fib_index0 = + ip4_fib_table_get_index_for_sw_if_index (sw_if_index0); + icmp0 = (icmp46_header_t *) udp0; + + next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, + rx_fib_index0, node, next0, thread_index, + &ses0, &dm0); + goto trace00; + } + + dm0 = snat_det_map_by_user (sm, &ip0->src_address); + if (PREDICT_FALSE (!dm0)) + { + nat_log_info ("no match for internal host %U", + format_ip4_address, &ip0->src_address); + next0 = NAT_DET_IN2OUT_NEXT_DROP; + b0->error = node->errors[NAT_DET_IN2OUT_ERROR_NO_TRANSLATION]; + goto trace00; + } + + snat_det_forward (dm0, &ip0->src_address, &new_addr0, &lo_port0); + + key0.ext_host_addr = ip0->dst_address; + key0.ext_host_port = tcp0->dst; + + ses0 = + snat_det_find_ses_by_in (dm0, &ip0->src_address, tcp0->src, key0); + if (PREDICT_FALSE (!ses0)) + { + for (i0 = 0; i0 < dm0->ports_per_host; i0++) + { + key0.out_port = clib_host_to_net_u16 (lo_port0 + + ((i0 + + clib_net_to_host_u16 + (tcp0->src)) % + dm0-> + ports_per_host)); + + if (snat_det_get_ses_by_out + (dm0, &ip0->src_address, key0.as_u64)) + continue; + + ses0 = + snat_det_ses_create (dm0, &ip0->src_address, tcp0->src, + &key0); + break; + } + if (PREDICT_FALSE (!ses0)) + { + /* too many sessions for user, send ICMP error packet */ + vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; + icmp4_error_set_vnet_buffer (b0, + ICMP4_destination_unreachable, + ICMP4_destination_unreachable_destination_unreachable_host, + 0); + next0 = NAT_DET_IN2OUT_NEXT_ICMP_ERROR; + goto trace00; + } + } + + new_port0 = ses0->out.out_port; + + old_addr0.as_u32 = ip0->src_address.as_u32; + ip0->src_address.as_u32 = new_addr0.as_u32; + vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm->outside_fib_index; + + sum0 = ip0->checksum; + sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32, + ip4_header_t, + src_address /* changed member */ ); + ip0->checksum = ip_csum_fold (sum0); + + if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP)) + { + if (tcp0->flags & TCP_FLAG_SYN) + ses0->state = SNAT_SESSION_TCP_SYN_SENT; + else if (tcp0->flags & TCP_FLAG_ACK + && ses0->state == SNAT_SESSION_TCP_SYN_SENT) + ses0->state = SNAT_SESSION_TCP_ESTABLISHED; + else if (tcp0->flags & TCP_FLAG_FIN + && ses0->state == SNAT_SESSION_TCP_ESTABLISHED) + ses0->state = SNAT_SESSION_TCP_FIN_WAIT; + else if (tcp0->flags & TCP_FLAG_ACK + && ses0->state == SNAT_SESSION_TCP_FIN_WAIT) + snat_det_ses_close (dm0, ses0); + else if (tcp0->flags & TCP_FLAG_FIN + && ses0->state == SNAT_SESSION_TCP_CLOSE_WAIT) + ses0->state = SNAT_SESSION_TCP_LAST_ACK; + else if (tcp0->flags == 0 + && ses0->state == SNAT_SESSION_UNKNOWN) + ses0->state = SNAT_SESSION_TCP_ESTABLISHED; + + old_port0 = tcp0->src; + tcp0->src = new_port0; + + sum0 = tcp0->checksum; + sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32, + ip4_header_t, + dst_address /* changed member */ ); + sum0 = ip_csum_update (sum0, old_port0, new_port0, + ip4_header_t /* cheat */ , + length /* changed member */ ); + mss_clamping (sm, tcp0, &sum0); + tcp0->checksum = ip_csum_fold (sum0); + } + else + { + ses0->state = SNAT_SESSION_UDP_ACTIVE; + old_port0 = udp0->src_port; + udp0->src_port = new_port0; + udp0->checksum = 0; + } + + switch (ses0->state) + { + case SNAT_SESSION_UDP_ACTIVE: + ses0->expire = now + sm->udp_timeout; + break; + case SNAT_SESSION_TCP_SYN_SENT: + case SNAT_SESSION_TCP_FIN_WAIT: + case SNAT_SESSION_TCP_CLOSE_WAIT: + case SNAT_SESSION_TCP_LAST_ACK: + ses0->expire = now + sm->tcp_transitory_timeout; + break; + case SNAT_SESSION_TCP_ESTABLISHED: + ses0->expire = now + sm->tcp_established_timeout; + break; + } + + trace00: + if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) + && (b0->flags & VLIB_BUFFER_IS_TRACED))) + { + nat_det_in2out_trace_t *t = + vlib_add_trace (vm, node, b0, sizeof (*t)); + t->sw_if_index = sw_if_index0; + t->next_index = next0; + t->session_index = ~0; + if (ses0) + t->session_index = ses0 - dm0->sessions; + } + + pkts_processed += next0 != NAT_DET_IN2OUT_NEXT_DROP; + + /* verify speculative enqueue, maybe switch current next frame */ + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, + to_next, n_left_to_next, + bi0, next0); + } + + vlib_put_next_frame (vm, node, next_index, n_left_to_next); + } + + vlib_node_increment_counter (vm, snat_det_in2out_node.index, + NAT_DET_IN2OUT_ERROR_IN2OUT_PACKETS, + pkts_processed); + return frame->n_vectors; +} + +/* *INDENT-OFF* */ +VLIB_REGISTER_NODE (snat_det_in2out_node) = { + .function = snat_det_in2out_node_fn, + .name = "nat44-det-in2out", + .vector_size = sizeof (u32), + .format_trace = format_nat_det_in2out_trace, + .type = VLIB_NODE_TYPE_INTERNAL, + .n_errors = ARRAY_LEN(nat_det_in2out_error_strings), + .error_strings = nat_det_in2out_error_strings, + .n_next_nodes = NAT_DET_IN2OUT_N_NEXT, + /* edit / add dispositions here */ + .next_nodes = { + [NAT_DET_IN2OUT_NEXT_DROP] = "error-drop", + [NAT_DET_IN2OUT_NEXT_LOOKUP] = "ip4-lookup", + [NAT_DET_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error", + }, +}; +/* *INDENT-ON* */ + +VLIB_NODE_FUNCTION_MULTIARCH (snat_det_in2out_node, snat_det_in2out_node_fn); + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |