diff options
Diffstat (limited to 'plugins/snat-plugin/snat/out2in.c')
| -rw-r--r-- | plugins/snat-plugin/snat/out2in.c | 601 |
1 files changed, 601 insertions, 0 deletions
diff --git a/plugins/snat-plugin/snat/out2in.c b/plugins/snat-plugin/snat/out2in.c new file mode 100644 index 00000000..0fa96c97 --- /dev/null +++ b/plugins/snat-plugin/snat/out2in.c @@ -0,0 +1,601 @@ +/* + * 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. + */ + +#include <vlib/vlib.h> +#include <vnet/vnet.h> +#include <vnet/pg/pg.h> + +#include <vnet/ip/ip.h> +#include <vnet/ethernet/ethernet.h> +#include <snat/snat.h> + +#include <vppinfra/hash.h> +#include <vppinfra/error.h> +#include <vppinfra/elog.h> + +vlib_node_registration_t snat_out2in_node; + +typedef struct { + u32 sw_if_index; + u32 next_index; + u32 session_index; +} snat_out2in_trace_t; + +/* packet trace format function */ +static u8 * format_snat_out2in_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 *); + snat_out2in_trace_t * t = va_arg (*args, snat_out2in_trace_t *); + + s = format (s, "SNAT_OUT2IN: sw_if_index %d, next index %d, session index %d", + t->sw_if_index, t->next_index, t->session_index); + return s; +} + +vlib_node_registration_t snat_out2in_node; + +#define foreach_snat_out2in_error \ +_(UNSUPPORTED_PROTOCOL, "Unsupported protocol") \ +_(OUT2IN_PACKETS, "Good out2in packets processed") \ +_(BAD_ICMP_TYPE, "icmp type not echo-reply") \ +_(NO_TRANSLATION, "No translation") + +typedef enum { +#define _(sym,str) SNAT_OUT2IN_ERROR_##sym, + foreach_snat_out2in_error +#undef _ + SNAT_OUT2IN_N_ERROR, +} snat_out2in_error_t; + +static char * snat_out2in_error_strings[] = { +#define _(sym,string) string, + foreach_snat_out2in_error +#undef _ +}; + +typedef enum { + SNAT_OUT2IN_NEXT_DROP, + SNAT_OUT2IN_N_NEXT, +} snat_out2in_next_t; + +static inline u32 icmp_out2in_slow_path (snat_main_t *sm, + vlib_buffer_t * b0, + ip4_header_t * ip0, + icmp46_header_t * icmp0, + u32 sw_if_index0, + u32 rx_fib_index0, + vlib_node_runtime_t * node, + u32 next0, f64 now) +{ + snat_session_key_t key0; + icmp_echo_header_t *echo0; + clib_bihash_kv_8_8_t kv0, value0; + snat_session_t * s0; + u32 new_addr0, old_addr0; + u16 old_id0, new_id0; + ip_csum_t sum0; + snat_runtime_t * rt = (snat_runtime_t *)node->runtime_data; + + echo0 = (icmp_echo_header_t *)(icmp0+1); + + key0.addr = ip0->dst_address; + key0.port = echo0->identifier; + key0.protocol = SNAT_PROTOCOL_ICMP; + key0.fib_index = rx_fib_index0; + + kv0.key = key0.as_u64; + + if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0)) + { + 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; + rt->cached_ip4_address = first_int_addr->as_u32; + } + + /* Don't NAT packet aimed at the intfc address */ + if (PREDICT_FALSE(ip0->dst_address.as_u32 == + rt->cached_ip4_address)) + return next0; + + b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION]; + return SNAT_OUT2IN_NEXT_DROP; + } + else + s0 = pool_elt_at_index (sm->sessions, value0.value); + + old_addr0 = ip0->dst_address.as_u32; + ip0->dst_address = s0->in2out.addr; + new_addr0 = ip0->dst_address.as_u32; + vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index; + + sum0 = ip0->checksum; + sum0 = ip_csum_update (sum0, old_addr0, new_addr0, + ip4_header_t, + dst_address /* changed member */); + ip0->checksum = ip_csum_fold (sum0); + + old_id0 = echo0->identifier; + new_id0 = s0->in2out.port; + echo0->identifier = new_id0; + + sum0 = icmp0->checksum; + sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t, + identifier); + icmp0->checksum = ip_csum_fold (sum0); + + /* Accounting, per-user LRU list maintenance */ + s0->last_heard = now; + s0->total_pkts++; + s0->total_bytes += vlib_buffer_length_in_chain (sm->vlib_main, b0); + clib_dlist_remove (sm->list_pool, s0->per_user_index); + clib_dlist_addtail (sm->list_pool, s0->per_user_list_head_index, + s0->per_user_index); + + return next0; +} + +static uword +snat_out2in_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, + vlib_frame_t * frame) +{ + u32 n_left_from, * from, * to_next; + snat_out2in_next_t next_index; + u32 pkts_processed = 0; + snat_main_t * sm = &snat_main; + ip_lookup_main_t * lm = sm->ip4_lookup_main; + ip_config_main_t * cm = &lm->rx_config_mains[VNET_UNICAST]; + f64 now = vlib_time_now (vm); + + 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 = SNAT_OUT2IN_NEXT_DROP; + u32 next1 = SNAT_OUT2IN_NEXT_DROP; + u32 sw_if_index0, sw_if_index1; + ip4_header_t * ip0, *ip1; + ip_csum_t sum0, sum1; + u32 new_addr0, old_addr0; + u16 new_port0, old_port0; + u32 new_addr1, old_addr1; + u16 new_port1, old_port1; + udp_header_t * udp0, * udp1; + tcp_header_t * tcp0, * tcp1; + icmp46_header_t * icmp0, * icmp1; + snat_session_key_t key0, key1; + u32 rx_fib_index0, rx_fib_index1; + u32 proto0, proto1; + snat_session_t * s0 = 0, * s1 = 0; + clib_bihash_kv_8_8_t kv0, kv1, value0, value1; + + /* 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); + + ip0 = vlib_buffer_get_current (b0); + udp0 = ip4_next_header (ip0); + tcp0 = (tcp_header_t *) udp0; + icmp0 = (icmp46_header_t *) udp0; + + sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX]; + rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index, + sw_if_index0); + + vnet_get_config_data (&cm->config_main, + &b0->current_config_index, + &next0, + 0 /* sizeof config data */); + proto0 = ~0; + proto0 = (ip0->protocol == IP_PROTOCOL_UDP) + ? SNAT_PROTOCOL_UDP : proto0; + proto0 = (ip0->protocol == IP_PROTOCOL_TCP) + ? SNAT_PROTOCOL_TCP : proto0; + proto0 = (ip0->protocol == IP_PROTOCOL_ICMP) + ? SNAT_PROTOCOL_ICMP : proto0; + + if (PREDICT_FALSE (proto0 == ~0)) + goto trace0; + + if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP)) + { + next0 = icmp_out2in_slow_path + (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node, + next0, now); + goto trace0; + } + + key0.addr = ip0->dst_address; + key0.port = udp0->dst_port; + key0.protocol = proto0; + key0.fib_index = rx_fib_index0; + + kv0.key = key0.as_u64; + + if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0)) + goto trace0; + else + s0 = pool_elt_at_index (sm->sessions, value0.value); + + old_addr0 = ip0->dst_address.as_u32; + ip0->dst_address = s0->in2out.addr; + new_addr0 = ip0->dst_address.as_u32; + vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index; + + sum0 = ip0->checksum; + sum0 = ip_csum_update (sum0, old_addr0, new_addr0, + ip4_header_t, + dst_address /* changed member */); + ip0->checksum = ip_csum_fold (sum0); + + if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP)) + { + old_port0 = tcp0->ports.dst; + tcp0->ports.dst = s0->in2out.port; + new_port0 = tcp0->ports.dst; + + sum0 = tcp0->checksum; + sum0 = ip_csum_update (sum0, old_addr0, new_addr0, + ip4_header_t, + dst_address /* changed member */); + + sum0 = ip_csum_update (sum0, old_port0, new_port0, + ip4_header_t /* cheat */, + length /* changed member */); + tcp0->checksum = ip_csum_fold(sum0); + } + else + { + old_port0 = udp0->dst_port; + udp0->dst_port = s0->in2out.port; + udp0->checksum = 0; + } + + /* Accounting, per-user LRU list maintenance */ + s0->last_heard = now; + s0->total_pkts++; + s0->total_bytes += vlib_buffer_length_in_chain (vm, b0); + clib_dlist_remove (sm->list_pool, s0->per_user_index); + clib_dlist_addtail (sm->list_pool, s0->per_user_list_head_index, + s0->per_user_index); + trace0: + + if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) + && (b0->flags & VLIB_BUFFER_IS_TRACED))) + { + snat_out2in_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 (s0) + t->session_index = s0 - sm->sessions; + } + + pkts_processed += next0 != SNAT_OUT2IN_NEXT_DROP; + + + ip1 = vlib_buffer_get_current (b1); + udp1 = ip4_next_header (ip1); + tcp1 = (tcp_header_t *) udp1; + icmp1 = (icmp46_header_t *) udp1; + + sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX]; + rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index, + sw_if_index1); + + vnet_get_config_data (&cm->config_main, + &b1->current_config_index, + &next1, + 0 /* sizeof config data */); + proto1 = ~0; + proto1 = (ip1->protocol == IP_PROTOCOL_UDP) + ? SNAT_PROTOCOL_UDP : proto1; + proto1 = (ip1->protocol == IP_PROTOCOL_TCP) + ? SNAT_PROTOCOL_TCP : proto1; + proto1 = (ip1->protocol == IP_PROTOCOL_ICMP) + ? SNAT_PROTOCOL_ICMP : proto1; + + if (PREDICT_FALSE (proto1 == ~0)) + goto trace1; + + if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP)) + { + next1 = icmp_out2in_slow_path + (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node, + next1, now); + goto trace1; + } + + key1.addr = ip1->dst_address; + key1.port = udp1->dst_port; + key1.protocol = proto1; + key1.fib_index = rx_fib_index1; + + kv1.key = key1.as_u64; + + if (clib_bihash_search_8_8 (&sm->out2in, &kv1, &value1)) + goto trace1; + else + s1 = pool_elt_at_index (sm->sessions, value1.value); + + old_addr1 = ip1->dst_address.as_u32; + ip1->dst_address = s1->in2out.addr; + new_addr1 = ip1->dst_address.as_u32; + vnet_buffer(b1)->sw_if_index[VLIB_TX] = s1->out2in.fib_index; + + sum1 = ip1->checksum; + sum1 = ip_csum_update (sum1, old_addr1, new_addr1, + ip4_header_t, + dst_address /* changed member */); + ip1->checksum = ip_csum_fold (sum1); + + if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP)) + { + old_port1 = tcp1->ports.dst; + tcp1->ports.dst = s1->in2out.port; + new_port1 = tcp1->ports.dst; + + sum1 = tcp1->checksum; + sum1 = ip_csum_update (sum1, old_addr1, new_addr1, + ip4_header_t, + dst_address /* changed member */); + + sum1 = ip_csum_update (sum1, old_port1, new_port1, + ip4_header_t /* cheat */, + length /* changed member */); + tcp1->checksum = ip_csum_fold(sum1); + } + else + { + old_port1 = udp1->dst_port; + udp1->dst_port = s1->in2out.port; + udp1->checksum = 0; + } + + /* Accounting, per-user LRU list maintenance */ + s1->last_heard = now; + s1->total_pkts++; + s1->total_bytes += vlib_buffer_length_in_chain (vm, b1); + clib_dlist_remove (sm->list_pool, s1->per_user_index); + clib_dlist_addtail (sm->list_pool, s1->per_user_list_head_index, + s1->per_user_index); + trace1: + + if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) + && (b1->flags & VLIB_BUFFER_IS_TRACED))) + { + snat_out2in_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 (s1) + t->session_index = s1 - sm->sessions; + } + + pkts_processed += next0 != SNAT_OUT2IN_NEXT_DROP; + pkts_processed += next1 != SNAT_OUT2IN_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 = SNAT_OUT2IN_NEXT_DROP; + u32 sw_if_index0; + ip4_header_t * ip0; + ip_csum_t sum0; + u32 new_addr0, old_addr0; + u16 new_port0, old_port0; + udp_header_t * udp0; + tcp_header_t * tcp0; + icmp46_header_t * icmp0; + snat_session_key_t key0; + u32 rx_fib_index0; + u32 proto0; + snat_session_t * s0 = 0; + clib_bihash_kv_8_8_t kv0, value0; + + /* 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); + + ip0 = vlib_buffer_get_current (b0); + udp0 = ip4_next_header (ip0); + tcp0 = (tcp_header_t *) udp0; + icmp0 = (icmp46_header_t *) udp0; + + sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX]; + rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index, + sw_if_index0); + + vnet_get_config_data (&cm->config_main, + &b0->current_config_index, + &next0, + 0 /* sizeof config data */); + proto0 = ~0; + proto0 = (ip0->protocol == IP_PROTOCOL_UDP) + ? SNAT_PROTOCOL_UDP : proto0; + proto0 = (ip0->protocol == IP_PROTOCOL_TCP) + ? SNAT_PROTOCOL_TCP : proto0; + proto0 = (ip0->protocol == IP_PROTOCOL_ICMP) + ? SNAT_PROTOCOL_ICMP : proto0; + + if (PREDICT_FALSE (proto0 == ~0)) + goto trace00; + + if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP)) + { + next0 = icmp_out2in_slow_path + (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node, + next0, now); + goto trace00; + } + + key0.addr = ip0->dst_address; + key0.port = udp0->dst_port; + key0.protocol = proto0; + key0.fib_index = rx_fib_index0; + + kv0.key = key0.as_u64; + + if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0)) + goto trace00; + else + s0 = pool_elt_at_index (sm->sessions, value0.value); + + old_addr0 = ip0->dst_address.as_u32; + ip0->dst_address = s0->in2out.addr; + new_addr0 = ip0->dst_address.as_u32; + vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index; + + sum0 = ip0->checksum; + sum0 = ip_csum_update (sum0, old_addr0, new_addr0, + ip4_header_t, + dst_address /* changed member */); + ip0->checksum = ip_csum_fold (sum0); + + if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP)) + { + old_port0 = tcp0->ports.dst; + tcp0->ports.dst = s0->in2out.port; + new_port0 = tcp0->ports.dst; + + sum0 = tcp0->checksum; + sum0 = ip_csum_update (sum0, old_addr0, new_addr0, + ip4_header_t, + dst_address /* changed member */); + + sum0 = ip_csum_update (sum0, old_port0, new_port0, + ip4_header_t /* cheat */, + length /* changed member */); + tcp0->checksum = ip_csum_fold(sum0); + } + else + { + old_port0 = udp0->dst_port; + udp0->dst_port = s0->in2out.port; + udp0->checksum = 0; + } + + /* Accounting, per-user LRU list maintenance */ + s0->last_heard = now; + s0->total_pkts++; + s0->total_bytes += vlib_buffer_length_in_chain (vm, b0); + clib_dlist_remove (sm->list_pool, s0->per_user_index); + clib_dlist_addtail (sm->list_pool, s0->per_user_list_head_index, + s0->per_user_index); + trace00: + + if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) + && (b0->flags & VLIB_BUFFER_IS_TRACED))) + { + snat_out2in_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 (s0) + t->session_index = s0 - sm->sessions; + } + + pkts_processed += next0 != SNAT_OUT2IN_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_out2in_node.index, + SNAT_OUT2IN_ERROR_OUT2IN_PACKETS, + pkts_processed); + return frame->n_vectors; +} + +VLIB_REGISTER_NODE (snat_out2in_node) = { + .function = snat_out2in_node_fn, + .name = "snat-out2in", + .vector_size = sizeof (u32), + .format_trace = format_snat_out2in_trace, + .type = VLIB_NODE_TYPE_INTERNAL, + + .n_errors = ARRAY_LEN(snat_out2in_error_strings), + .error_strings = snat_out2in_error_strings, + + .runtime_data_bytes = sizeof (snat_runtime_t), + + .n_next_nodes = SNAT_OUT2IN_N_NEXT, + + /* edit / add dispositions here */ + .next_nodes = { + [SNAT_OUT2IN_NEXT_DROP] = "error-drop", + }, +}; +VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_node, snat_out2in_node_fn); |