diff options
Diffstat (limited to 'src/plugins/nat/dslite_out2in.c')
| -rw-r--r-- | src/plugins/nat/dslite_out2in.c | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/src/plugins/nat/dslite_out2in.c b/src/plugins/nat/dslite_out2in.c new file mode 100644 index 00000000000..802b2a91544 --- /dev/null +++ b/src/plugins/nat/dslite_out2in.c @@ -0,0 +1,297 @@ +/* + * Copyright (c) 2017 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 <nat/dslite.h> + +vlib_node_registration_t dslite_out2in_node; + +typedef enum +{ + DSLITE_OUT2IN_NEXT_IP4_LOOKUP, + DSLITE_OUT2IN_NEXT_IP6_LOOKUP, + DSLITE_OUT2IN_NEXT_DROP, + DSLITE_OUT2IN_N_NEXT, +} dslite_out2in_next_t; + +static char *dslite_out2in_error_strings[] = { +#define _(sym,string) string, + foreach_dslite_error +#undef _ +}; + +static inline u32 +dslite_icmp_out2in (dslite_main_t * dm, ip4_header_t * ip4, + dslite_session_t ** sp, u32 next, u8 * error, + u32 thread_index) +{ + dslite_session_t *s = 0; + icmp46_header_t *icmp = ip4_next_header (ip4); + clib_bihash_kv_8_8_t kv, value; + snat_session_key_t key; + u32 n = next; + icmp_echo_header_t *echo; + u32 new_addr, old_addr; + u16 old_id, new_id; + ip_csum_t sum; + + echo = (icmp_echo_header_t *) (icmp + 1); + + if (icmp_is_error_message (icmp) || (icmp->type != ICMP4_echo_reply)) + { + n = DSLITE_OUT2IN_NEXT_DROP; + *error = DSLITE_ERROR_BAD_ICMP_TYPE; + goto done; + } + + key.addr = ip4->dst_address; + key.port = echo->identifier; + key.protocol = SNAT_PROTOCOL_ICMP; + key.fib_index = 0; + kv.key = key.as_u64; + + if (clib_bihash_search_8_8 + (&dm->per_thread_data[thread_index].out2in, &kv, &value)) + { + next = DSLITE_OUT2IN_NEXT_DROP; + *error = DSLITE_ERROR_NO_TRANSLATION; + goto done; + } + else + { + s = + pool_elt_at_index (dm->per_thread_data[thread_index].sessions, + value.value); + } + + old_id = echo->identifier; + echo->identifier = new_id = s->in2out.port; + sum = icmp->checksum; + sum = ip_csum_update (sum, old_id, new_id, icmp_echo_header_t, identifier); + icmp->checksum = ip_csum_fold (sum); + + old_addr = ip4->dst_address.as_u32; + ip4->dst_address = s->in2out.addr; + new_addr = ip4->dst_address.as_u32; + + sum = ip4->checksum; + sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address); + ip4->checksum = ip_csum_fold (sum); + +done: + *sp = s; + return n; +} + +static uword +dslite_out2in_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node, + vlib_frame_t * frame) +{ + u32 n_left_from, *from, *to_next; + dslite_out2in_next_t next_index; + vlib_node_runtime_t *error_node; + u32 thread_index = vlib_get_thread_index (); + f64 now = vlib_time_now (vm); + dslite_main_t *dm = &dslite_main; + + error_node = vlib_node_get_runtime (vm, dslite_out2in_node.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 > 0 && n_left_to_next > 0) + { + u32 bi0; + vlib_buffer_t *b0; + u32 next0 = DSLITE_OUT2IN_NEXT_IP6_LOOKUP; + u8 error0 = DSLITE_ERROR_OUT2IN; + ip4_header_t *ip40; + ip6_header_t *ip60; + u32 proto0; + udp_header_t *udp0; + tcp_header_t *tcp0; + clib_bihash_kv_8_8_t kv0, value0; + snat_session_key_t key0; + dslite_session_t *s0 = 0; + ip_csum_t sum0; + u32 new_addr0, old_addr0; + u16 new_port0, old_port0; + + /* 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); + ip40 = vlib_buffer_get_current (b0); + proto0 = ip_proto_to_snat_proto (ip40->protocol); + + if (PREDICT_FALSE (proto0 == ~0)) + { + error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL; + next0 = DSLITE_OUT2IN_NEXT_DROP; + goto trace0; + } + + if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP)) + { + next0 = + dslite_icmp_out2in (dm, ip40, &s0, next0, &error0, + thread_index); + if (PREDICT_FALSE (next0 == DSLITE_OUT2IN_NEXT_DROP)) + goto trace0; + + goto encap0; + } + + udp0 = ip4_next_header (ip40); + tcp0 = (tcp_header_t *) udp0; + + key0.addr = ip40->dst_address; + key0.port = udp0->dst_port; + key0.protocol = proto0; + key0.fib_index = 0; + kv0.key = key0.as_u64; + + if (clib_bihash_search_8_8 + (&dm->per_thread_data[thread_index].out2in, &kv0, &value0)) + { + next0 = DSLITE_OUT2IN_NEXT_DROP; + error0 = DSLITE_ERROR_NO_TRANSLATION; + goto trace0; + } + else + { + s0 = + pool_elt_at_index (dm->per_thread_data[thread_index].sessions, + value0.value); + } + + old_addr0 = ip40->dst_address.as_u32; + ip40->dst_address = s0->in2out.addr; + new_addr0 = ip40->dst_address.as_u32; + + sum0 = ip40->checksum; + sum0 = + ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t, + dst_address); + ip40->checksum = ip_csum_fold (sum0); + + if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP)) + { + old_port0 = tcp0->dst_port; + tcp0->dst_port = s0->in2out.port; + new_port0 = tcp0->dst_port; + + sum0 = tcp0->checksum; + sum0 = + ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t, + dst_address); + sum0 = + ip_csum_update (sum0, old_port0, new_port0, ip4_header_t, + length); + tcp0->checksum = ip_csum_fold (sum0); + } + else + { + old_port0 = udp0->dst_port; + udp0->dst_port = s0->in2out.port; + udp0->checksum = 0; + } + + encap0: + /* Construct IPv6 header */ + vlib_buffer_advance (b0, -(sizeof (ip6_header_t))); + ip60 = vlib_buffer_get_current (b0); + ip60->ip_version_traffic_class_and_flow_label = + clib_host_to_net_u32 ((6 << 28) + (ip40->tos << 20)); + ip60->payload_length = ip40->length; + ip60->protocol = IP_PROTOCOL_IP_IN_IP; + ip60->hop_limit = ip40->ttl; + ip60->src_address.as_u64[0] = dm->aftr_ip6_addr.as_u64[0]; + ip60->src_address.as_u64[1] = dm->aftr_ip6_addr.as_u64[1]; + ip60->dst_address.as_u64[0] = s0->in2out.softwire_id.as_u64[0]; + ip60->dst_address.as_u64[1] = s0->in2out.softwire_id.as_u64[1]; + + /* Accounting */ + s0->last_heard = now; + s0->total_pkts++; + s0->total_bytes += vlib_buffer_length_in_chain (vm, b0); + /* Per-B4 LRU list maintenance */ + clib_dlist_remove (dm->per_thread_data[thread_index].list_pool, + s0->per_b4_index); + clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool, + s0->per_b4_list_head_index, s0->per_b4_index); + trace0: + if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) + && (b0->flags & VLIB_BUFFER_IS_TRACED))) + { + dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); + t->next_index = next0; + t->session_index = ~0; + if (s0) + t->session_index = + s0 - dm->per_thread_data[thread_index].sessions; + } + + b0->error = error_node->errors[error0]; + + /* 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); + } + + return frame->n_vectors; +} + +/* *INDENT-OFF* */ +VLIB_REGISTER_NODE (dslite_out2in_node) = { + .function = dslite_out2in_node_fn, + .name = "dslite-out2in", + .vector_size = sizeof (u32), + .format_trace = format_dslite_trace, + .type = VLIB_NODE_TYPE_INTERNAL, + .n_errors = ARRAY_LEN (dslite_out2in_error_strings), + .error_strings = dslite_out2in_error_strings, + .n_next_nodes = DSLITE_OUT2IN_N_NEXT, + /* edit / add dispositions here */ + .next_nodes = { + [DSLITE_OUT2IN_NEXT_DROP] = "error-drop", + [DSLITE_OUT2IN_NEXT_IP4_LOOKUP] = "ip4-lookup", + [DSLITE_OUT2IN_NEXT_IP6_LOOKUP] = "ip6-lookup", + }, +}; +/* *INDENT-ON* */ + +VLIB_NODE_FUNCTION_MULTIARCH (dslite_out2in_node, dslite_out2in_node_fn); + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |