2 * Copyright (c) 2020 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vlibmemory/api.h>
17 #include <cnat/cnat_node.h>
18 #include <cnat/cnat_snat.h>
20 typedef enum cnat_snat_next_
26 typedef struct cnat_snat_trace_
29 cnat_session_t session;
32 vlib_node_registration_t cnat_snat_ip4_node;
33 vlib_node_registration_t cnat_snat_ip6_node;
36 format_cnat_snat_trace (u8 * s, va_list * args)
38 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
39 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
40 cnat_snat_trace_t *t = va_arg (*args, cnat_snat_trace_t *);
43 s = format (s, "found: %U", format_cnat_session, &t->session, 1);
45 s = format (s, "not found");
49 /* CNat sub for source NAT as a feature arc on ip[46]-unicast
50 This node's sub shouldn't apply to the same flows as
53 cnat_snat_inline (vlib_main_t * vm,
54 vlib_node_runtime_t * node,
56 cnat_node_ctx_t * ctx, int rv, cnat_session_t * session)
58 cnat_main_t *cm = &cnat_main;
67 if (AF_IP4 == ctx->af)
69 ip4 = vlib_buffer_get_current (b);
70 iproto = ip4->protocol;
71 udp0 = (udp_header_t *) (ip4 + 1);
75 ip6 = vlib_buffer_get_current (b);
76 iproto = ip6->protocol;
77 udp0 = (udp_header_t *) (ip6 + 1);
80 /* By default don't follow previous next0 */
81 vnet_feature_next (&arc_next0, b);
84 if (iproto != IP_PROTOCOL_UDP && iproto != IP_PROTOCOL_TCP)
92 /* session table hit */
93 cnat_timestamp_update (session->value.cs_ts_index, ctx->now);
97 ip46_address_t ip46_dst_address;
98 if (AF_IP4 == ctx->af)
99 ip46_address_set_ip4 (&ip46_dst_address, &ip4->dst_address);
101 ip46_address_set_ip6 (&ip46_dst_address, &ip6->dst_address);
102 rv = cnat_search_snat_prefix (&ip46_dst_address, ctx->af);
105 /* Prefix table hit, we shouldn't source NAT */
108 /* New flow, create the sessions if necessary. session will be a snat
109 session, and rsession will be a dnat session
110 Note: packet going through this path are going to the outside,
111 so they will never hit the NAT again (they are not going towards
113 if (AF_IP4 == ctx->af)
115 ip46_address_set_ip4 (&session->value.cs_ip[VLIB_RX],
117 ip46_address_set_ip4 (&session->value.cs_ip[VLIB_TX],
122 ip46_address_set_ip6 (&session->value.cs_ip[VLIB_RX],
124 ip46_address_set_ip6 (&session->value.cs_ip[VLIB_TX],
128 /* Port allocation, first try to use the original port, allocate one
129 if it is already used */
130 sport = udp0->src_port;
131 rv = cnat_allocate_port (cm, &sport);
134 vlib_node_increment_counter (vm, cnat_snat_ip4_node.index,
135 CNAT_ERROR_EXHAUSTED_PORTS, 1);
136 next0 = CNAT_SNAT_NEXT_DROP;
140 session->value.cs_port[VLIB_RX] = sport;
141 session->value.cs_port[VLIB_TX] = udp0->dst_port;
142 session->value.cs_lbi = INDEX_INVALID;
143 session->value.flags =
144 CNAT_SESSION_FLAG_NO_CLIENT | CNAT_SESSION_FLAG_ALLOC_PORT;
146 cnat_session_create (session, ctx, CNAT_SESSION_FLAG_HAS_SNAT);
150 if (AF_IP4 == ctx->af)
151 cnat_translation_ip4 (session, ip4, udp0);
153 cnat_translation_ip6 (session, ip6, udp0);
156 if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
158 cnat_snat_trace_t *t;
160 t = vlib_add_trace (vm, node, b, sizeof (*t));
163 clib_memcpy (&t->session, session, sizeof (t->session));
168 VLIB_NODE_FN (cnat_snat_ip4_node) (vlib_main_t * vm,
169 vlib_node_runtime_t * node,
170 vlib_frame_t * frame)
172 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
173 return cnat_node_inline (vm, node, frame, cnat_snat_inline, AF_IP4,
175 return cnat_node_inline (vm, node, frame, cnat_snat_inline, AF_IP4,
179 VLIB_NODE_FN (cnat_snat_ip6_node) (vlib_main_t * vm,
180 vlib_node_runtime_t * node,
181 vlib_frame_t * frame)
183 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
184 return cnat_node_inline (vm, node, frame, cnat_snat_inline, AF_IP6,
186 return cnat_node_inline (vm, node, frame, cnat_snat_inline, AF_IP6,
191 VLIB_REGISTER_NODE (cnat_snat_ip4_node) =
193 .name = "ip4-cnat-snat",
194 .vector_size = sizeof (u32),
195 .format_trace = format_cnat_snat_trace,
196 .type = VLIB_NODE_TYPE_INTERNAL,
197 .n_errors = CNAT_N_ERROR,
198 .error_strings = cnat_error_strings,
199 .n_next_nodes = CNAT_SNAT_N_NEXT,
202 [CNAT_SNAT_NEXT_DROP] = "ip4-drop",
206 VLIB_REGISTER_NODE (cnat_snat_ip6_node) =
208 .name = "ip6-cnat-snat",
209 .vector_size = sizeof (u32),
210 .format_trace = format_cnat_snat_trace,
211 .type = VLIB_NODE_TYPE_INTERNAL,
212 .n_errors = CNAT_N_ERROR,
213 .error_strings = cnat_error_strings,
214 .n_next_nodes = CNAT_SNAT_N_NEXT,
217 [CNAT_SNAT_NEXT_DROP] = "ip6-drop",
223 VNET_FEATURE_INIT (cnat_snat_ip4_node, static) =
225 .arc_name = "ip4-unicast",.node_name = "ip4-cnat-snat",};
227 VNET_FEATURE_INIT (cnat_snat_ip6_node, static) =
229 .arc_name = "ip6-unicast",.node_name = "ip6-cnat-snat",};
232 * fd.io coding-style-patch-verification: ON
235 * eval: (c-set-style "gnu")