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_translation.h>
20 #include <vnet/dpo/load_balance.h>
21 #include <vnet/dpo/load_balance_map.h>
23 typedef struct cnat_translation_trace_t_
25 cnat_session_t session;
26 cnat_translation_t tr;
30 } cnat_translation_trace_t;
32 typedef enum cnat_translation_next_t_
34 CNAT_TRANSLATION_NEXT_DROP,
35 CNAT_TRANSLATION_NEXT_LOOKUP,
36 CNAT_TRANSLATION_N_NEXT,
37 } cnat_translation_next_t;
39 vlib_node_registration_t cnat_vip_ip4_node;
40 vlib_node_registration_t cnat_vip_ip6_node;
43 format_cnat_translation_trace (u8 * s, va_list * args)
45 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
46 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
47 cnat_translation_trace_t *t =
48 va_arg (*args, cnat_translation_trace_t *);
51 s = format (s, "found: %U", format_cnat_session, &t->session, 1);
52 else if (t->created_session)
53 s = format (s, "created: %U\n tr: %U",
54 format_cnat_session, &t->session, 1,
55 format_cnat_translation,
58 s = format (s, "tr pass: %U", format_cnat_translation,
61 s = format (s, "not found");
65 /* CNat sub for NAT behind a fib entry (VIP or interposed real IP) */
67 cnat_vip_inline (vlib_main_t * vm,
68 vlib_node_runtime_t * node,
70 cnat_node_ctx_t * ctx, int rv, cnat_session_t * session)
72 vlib_combined_counter_main_t *cntm = &cnat_translation_counters;
73 cnat_main_t *cm = &cnat_main;
74 const cnat_translation_t *ct = NULL;
75 ip4_header_t *ip4 = NULL;
77 ip6_header_t *ip6 = NULL;
82 int created_session = 0;
83 if (AF_IP4 == ctx->af)
85 ip4 = vlib_buffer_get_current (b);
86 iproto = ip4->protocol;
87 udp0 = (udp_header_t *) (ip4 + 1);
91 ip6 = vlib_buffer_get_current (b);
92 iproto = ip6->protocol;
93 udp0 = (udp_header_t *) (ip6 + 1);
96 cc = cnat_client_get (vnet_buffer (b)->ip.adj_index[VLIB_TX]);
98 if (iproto != IP_PROTOCOL_UDP && iproto != IP_PROTOCOL_TCP)
100 /* Dont translate & follow the fib programming */
101 next0 = cc->cc_parent.dpoi_next_node;
102 vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
106 ct = cnat_find_translation (cc->parent_cci,
107 clib_host_to_net_u16 (udp0->dst_port),
112 /* session table hit */
113 cnat_timestamp_update (session->value.cs_ts_index, ctx->now);
117 /* Translate & follow the translation given LB */
118 next0 = ct->ct_lb.dpoi_next_node;
119 vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
121 else if (session->value.flags & CNAT_SESSION_FLAG_HAS_SNAT)
123 /* The return needs DNAT, so we need an additionnal
124 * lookup after translation */
125 next0 = CNAT_TRANSLATION_NEXT_LOOKUP;
129 /* Translate & follow the fib programming */
130 next0 = cc->cc_parent.dpoi_next_node;
131 vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
138 /* Dont translate & Follow the fib programming */
139 vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
140 next0 = cc->cc_parent.dpoi_next_node;
144 /* New flow, create the sessions */
145 const load_balance_t *lb0;
147 u32 hash_c0, bucket0;
148 u32 rsession_flags = 0;
149 const dpo_id_t *dpo0;
151 lb0 = load_balance_get (ct->ct_lb.dpoi_index);
152 if (!lb0->lb_n_buckets)
154 /* Dont translate & Follow the fib programming */
155 vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
156 next0 = cc->cc_parent.dpoi_next_node;
160 /* session table miss */
161 hash_c0 = (AF_IP4 == ctx->af ?
162 ip4_compute_flow_hash (ip4, lb0->lb_hash_config) :
163 ip6_compute_flow_hash (ip6, lb0->lb_hash_config));
164 bucket0 = hash_c0 & lb0->lb_n_buckets_minus_1;
165 dpo0 = load_balance_get_fwd_bucket (lb0, bucket0);
167 /* add the session */
168 trk0 = &ct->ct_paths[bucket0];
170 ip46_address_copy (&session->value.cs_ip[VLIB_TX],
171 &trk0->ct_ep[VLIB_TX].ce_ip.ip);
172 if (ip_address_is_zero (&trk0->ct_ep[VLIB_RX].ce_ip))
174 if (AF_IP4 == ctx->af)
175 ip46_address_set_ip4 (&session->value.cs_ip[VLIB_RX],
178 ip46_address_set_ip6 (&session->value.cs_ip[VLIB_RX],
183 /* We source NAT with the translation */
184 rsession_flags |= CNAT_SESSION_FLAG_HAS_SNAT;
185 ip46_address_copy (&session->value.cs_ip[VLIB_RX],
186 &trk0->ct_ep[VLIB_RX].ce_ip.ip);
188 session->value.cs_port[VLIB_TX] =
189 clib_host_to_net_u16 (trk0->ct_ep[VLIB_TX].ce_port);
190 session->value.cs_port[VLIB_RX] =
191 clib_host_to_net_u16 (trk0->ct_ep[VLIB_RX].ce_port);
193 session->value.flags = 0;
194 if (!session->value.cs_port[VLIB_RX])
197 sport = udp0->src_port;
198 /* Allocate a port only if asked and if we actually sNATed */
199 if ((ct->flags & CNAT_TRANSLATION_FLAG_ALLOCATE_PORT)
200 && (rsession_flags & CNAT_SESSION_FLAG_HAS_SNAT)) {
201 sport = 0; /* force allocation */
202 session->value.flags |= CNAT_SESSION_FLAG_ALLOC_PORT;
203 rv = cnat_allocate_port (cm, &sport);
206 vlib_node_increment_counter (vm, cnat_vip_ip4_node.index,
207 CNAT_ERROR_EXHAUSTED_PORTS, 1);
208 next0 = CNAT_TRANSLATION_NEXT_DROP;
213 session->value.cs_port[VLIB_RX] = sport;
215 session->value.cs_lbi = dpo0->dpoi_index;
217 cnat_client_cnt_session (cc);
218 cnat_session_create (session, ctx, rsession_flags);
221 next0 = ct->ct_lb.dpoi_next_node;
222 vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
226 if (AF_IP4 == ctx->af)
227 cnat_translation_ip4 (session, ip4, udp0);
229 cnat_translation_ip6 (session, ip6, udp0);
233 cti = ct - cnat_translation_pool;
234 vlib_increment_combined_counter (cntm, ctx->thread_index, cti, 1,
235 vlib_buffer_length_in_chain (vm, b));
239 if (PREDICT_FALSE (ctx->do_trace))
241 cnat_translation_trace_t *t;
243 t = vlib_add_trace (vm, node, b, sizeof (*t));
245 t->found_session = !rv;
246 t->created_session = created_session;
247 if (t->found_session || t->created_session)
248 clib_memcpy (&t->session, session, sizeof (t->session));
249 t->has_tr = (NULL != ct);
251 clib_memcpy (&t->tr, ct, sizeof (cnat_translation_t));
256 VLIB_NODE_FN (cnat_vip_ip4_node) (vlib_main_t * vm,
257 vlib_node_runtime_t * node,
258 vlib_frame_t * frame)
260 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
261 return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP4,
263 return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP4,
267 VLIB_NODE_FN (cnat_vip_ip6_node) (vlib_main_t * vm,
268 vlib_node_runtime_t * node,
269 vlib_frame_t * frame)
271 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
272 return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP6,
274 return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP6,
279 VLIB_REGISTER_NODE (cnat_vip_ip4_node) =
281 .name = "ip4-cnat-tx",
282 .vector_size = sizeof (u32),
283 .format_trace = format_cnat_translation_trace,
284 .type = VLIB_NODE_TYPE_INTERNAL,
286 .n_next_nodes = CNAT_TRANSLATION_N_NEXT,
289 [CNAT_TRANSLATION_NEXT_DROP] = "ip4-drop",
290 [CNAT_TRANSLATION_NEXT_LOOKUP] = "ip4-lookup",
293 VLIB_REGISTER_NODE (cnat_vip_ip6_node) =
295 .name = "ip6-cnat-tx",
296 .vector_size = sizeof (u32),
297 .format_trace = format_cnat_translation_trace,
298 .type = VLIB_NODE_TYPE_INTERNAL,
300 .n_next_nodes = CNAT_TRANSLATION_N_NEXT,
303 [CNAT_TRANSLATION_NEXT_DROP] = "ip6-drop",
304 [CNAT_TRANSLATION_NEXT_LOOKUP] = "ip6-lookup",