/* * Copyright (c) 2020 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 #include #include #include #include typedef enum cnat_snat_next_ { CNAT_SNAT_NEXT_DROP, CNAT_SNAT_N_NEXT, } cnat_snat_next_t; typedef struct cnat_snat_trace_ { cnat_session_t session; u32 found_session; u32 created_session; } cnat_snat_trace_t; vlib_node_registration_t cnat_snat_ip4_node; vlib_node_registration_t cnat_snat_ip6_node; static u8 * format_cnat_snat_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 *); cnat_snat_trace_t *t = va_arg (*args, cnat_snat_trace_t *); if (t->found_session) s = format (s, "found: %U", format_cnat_session, &t->session, 1); else if (t->created_session) s = format (s, "created: %U\n tr: %U", format_cnat_session, &t->session, 1); else s = format (s, "not found"); return s; } /* CNat sub for source NAT as a feature arc on ip[46]-unicast This node's sub shouldn't apply to the same flows as cnat_vip_inline */ always_inline uword cnat_snat_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_buffer_t * b, cnat_node_ctx_t * ctx, int rv, cnat_session_t * session) { cnat_main_t *cm = &cnat_main; int created_session = 0; ip4_header_t *ip4; ip_protocol_t iproto; ip6_header_t *ip6; udp_header_t *udp0; u32 arc_next0; u16 next0; u16 sport; if (AF_IP4 == ctx->af) { ip4 = vlib_buffer_get_current (b); iproto = ip4->protocol; udp0 = (udp_header_t *) (ip4 + 1); } else { ip6 = vlib_buffer_get_current (b); iproto = ip6->protocol; udp0 = (udp_header_t *) (ip6 + 1); } /* By default don't follow previous next0 */ vnet_feature_next (&arc_next0, b); next0 = arc_next0; if (iproto != IP_PROTOCOL_UDP && iproto != IP_PROTOCOL_TCP && iproto != IP_PROTOCOL_ICMP && iproto != IP_PROTOCOL_ICMP6) { /* Dont translate */ goto trace; } if (!rv) { /* session table hit */ cnat_timestamp_update (session->value.cs_ts_index, ctx->now); } else { ip46_address_t ip46_dst_address; if (AF_IP4 == ctx->af) ip46_address_set_ip4 (&ip46_dst_address, &ip4->dst_address); else ip46_address_set_ip6 (&ip46_dst_address, &ip6->dst_address); rv = cnat_search_snat_prefix (&ip46_dst_address, ctx->af); if (!rv) { /* Prefix table hit, we shouldn't source NAT */ goto trace; } /* New flow, create the sessions if necessary. session will be a snat session, and rsession will be a dnat session Note: packet going through this path are going to the outside, so they will never hit the NAT again (they are not going towards a VIP) */ if (AF_IP4 == ctx->af) { ip46_address_set_ip4 (&session->value.cs_ip[VLIB_RX], &ip_addr_v4 (&cm->snat_ip4.ce_ip)); ip46_address_set_ip4 (&session->value.cs_ip[VLIB_TX], &ip4->dst_address); } else { ip46_address_set_ip6 (&session->value.cs_ip[VLIB_RX], &ip_addr_v6 (&cm->snat_ip6.ce_ip)); ip46_address_set_ip6 (&session->value.cs_ip[VLIB_TX], &ip6->dst_address); } sport = 0; rv = cnat_allocate_port (&sport, iproto); if (rv) { vlib_node_increment_counter (vm, cnat_snat_ip4_node.index, CNAT_ERROR_EXHAUSTED_PORTS, 1); next0 = CNAT_SNAT_NEXT_DROP; goto trace; } session->value.cs_port[VLIB_RX] = sport; session->value.cs_port[VLIB_TX] = sport; if (iproto == IP_PROTOCOL_TCP || iproto == IP_PROTOCOL_UDP) session->value.cs_port[VLIB_TX] = udp0->dst_port; session->value.cs_lbi = INDEX_INVALID; session->value.flags = CNAT_SESSION_FLAG_NO_CLIENT | CNAT_SESSION_FLAG_ALLOC_PORT; created_session = 1; cnat_session_create (session, ctx, CNAT_SESSION_FLAG_HAS_SNAT); } if (AF_IP4 == ctx->af) cnat_translation_ip4 (session, ip4, udp0); else cnat_translation_ip6 (session, ip6, udp0); trace: if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED)) { cnat_snat_trace_t *t; t = vlib_add_trace (vm, node, b, sizeof (*t)); t->found_session = !rv; t->created_session = created_session; if (t->found_session || t->created_session) clib_memcpy (&t->session, session, sizeof (t->session)); } return next0; } VLIB_NODE_FN (cnat_snat_ip4_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE))) return cnat_node_inline (vm, node, frame, cnat_snat_inline, AF_IP4, 1 /* do_trace */ ); return cnat_node_inline (vm, node, frame, cnat_snat_inline, AF_IP4, 0 /* do_trace */ ); } VLIB_NODE_FN (cnat_snat_ip6_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE))) return cnat_node_inline (vm, node, frame, cnat_snat_inline, AF_IP6, 1 /* do_trace */ ); return cnat_node_inline (vm, node, frame, cnat_snat_inline, AF_IP6, 0 /* do_trace */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (cnat_snat_ip4_node) = { .name = "ip4-cnat-snat", .vector_size = sizeof (u32), .format_trace = format_cnat_snat_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = CNAT_N_ERROR, .error_strings = cnat_error_strings, .n_next_nodes = CNAT_SNAT_N_NEXT, .next_nodes = { [CNAT_SNAT_NEXT_DROP] = "ip4-drop", } }; VLIB_REGISTER_NODE (cnat_snat_ip6_node) = { .name = "ip6-cnat-snat", .vector_size = sizeof (u32), .format_trace = format_cnat_snat_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = CNAT_N_ERROR, .error_strings = cnat_error_strings, .n_next_nodes = CNAT_SNAT_N_NEXT, .next_nodes = { [CNAT_SNAT_NEXT_DROP] = "ip6-drop", } }; VNET_FEATURE_INIT (cnat_snat_ip4_node, static) = { .arc_name = "ip4-unicast", .node_name = "ip4-cnat-snat", }; VNET_FEATURE_INIT (cnat_snat_ip6_node, static) = { .arc_name = "ip6-unicast", .node_name = "ip6-cnat-snat", }; /* *INDENT-ON* */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */