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
99 && iproto != IP_PROTOCOL_ICMP && iproto != IP_PROTOCOL_ICMP6)
101 /* Dont translate & follow the fib programming */
102 next0 = cc->cc_parent.dpoi_next_node;
103 vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
107 ct = cnat_find_translation (cc->parent_cci,
108 clib_host_to_net_u16 (udp0->dst_port),
113 /* session table hit */
114 cnat_timestamp_update (session->value.cs_ts_index, ctx->now);
118 /* Translate & follow the translation given LB */
119 next0 = ct->ct_lb.dpoi_next_node;
120 vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
122 else if (session->value.flags & CNAT_SESSION_FLAG_HAS_SNAT)
124 /* The return needs DNAT, so we need an additionnal
125 * lookup after translation */
126 next0 = CNAT_TRANSLATION_NEXT_LOOKUP;
130 /* Translate & follow the fib programming */
131 next0 = cc->cc_parent.dpoi_next_node;
132 vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
139 /* Dont translate & Follow the fib programming */
140 vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
141 next0 = cc->cc_parent.dpoi_next_node;
145 /* New flow, create the sessions */
146 const load_balance_t *lb0;
148 u32 hash_c0, bucket0;
149 u32 rsession_flags = 0;
150 const dpo_id_t *dpo0;
152 lb0 = load_balance_get (ct->ct_lb.dpoi_index);
153 if (!lb0->lb_n_buckets)
155 /* Dont translate & Follow the fib programming */
156 vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
157 next0 = cc->cc_parent.dpoi_next_node;
161 /* session table miss */
162 hash_c0 = (AF_IP4 == ctx->af ?
163 ip4_compute_flow_hash (ip4, lb0->lb_hash_config) :
164 ip6_compute_flow_hash (ip6, lb0->lb_hash_config));
165 bucket0 = hash_c0 & lb0->lb_n_buckets_minus_1;
166 dpo0 = load_balance_get_fwd_bucket (lb0, bucket0);
168 /* add the session */
169 trk0 = &ct->ct_paths[bucket0];
171 ip46_address_copy (&session->value.cs_ip[VLIB_TX],
172 &trk0->ct_ep[VLIB_TX].ce_ip.ip);
173 if (ip_address_is_zero (&trk0->ct_ep[VLIB_RX].ce_ip))
175 if (AF_IP4 == ctx->af)
176 ip46_address_set_ip4 (&session->value.cs_ip[VLIB_RX],
179 ip46_address_set_ip6 (&session->value.cs_ip[VLIB_RX],
184 /* We source NAT with the translation */
185 rsession_flags |= CNAT_SESSION_FLAG_HAS_SNAT;
186 ip46_address_copy (&session->value.cs_ip[VLIB_RX],
187 &trk0->ct_ep[VLIB_RX].ce_ip.ip);
189 session->value.cs_port[VLIB_TX] =
190 clib_host_to_net_u16 (trk0->ct_ep[VLIB_TX].ce_port);
191 session->value.cs_port[VLIB_RX] =
192 clib_host_to_net_u16 (trk0->ct_ep[VLIB_RX].ce_port);
194 session->value.flags = 0;
195 if (!session->value.cs_port[VLIB_RX])
198 sport = udp0->src_port;
199 /* Allocate a port only if asked and if we actually sNATed */
200 if ((ct->flags & CNAT_TRANSLATION_FLAG_ALLOCATE_PORT)
201 && (rsession_flags & CNAT_SESSION_FLAG_HAS_SNAT)) {
202 sport = 0; /* force allocation */
203 session->value.flags |= CNAT_SESSION_FLAG_ALLOC_PORT;
204 rv = cnat_allocate_port (cm, &sport);
207 vlib_node_increment_counter (vm, cnat_vip_ip4_node.index,
208 CNAT_ERROR_EXHAUSTED_PORTS, 1);
209 next0 = CNAT_TRANSLATION_NEXT_DROP;
214 session->value.cs_port[VLIB_RX] = sport;
216 session->value.cs_lbi = dpo0->dpoi_index;
218 /* refcnt session in current client */
219 cnat_client_cnt_session (cc);
220 cnat_session_create (session, ctx, rsession_flags);
223 next0 = ct->ct_lb.dpoi_next_node;
224 vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
227 if (AF_IP4 == ctx->af)
228 cnat_translation_ip4 (session, ip4, udp0);
230 cnat_translation_ip6 (session, ip6, udp0);
234 cti = ct - cnat_translation_pool;
235 vlib_increment_combined_counter (cntm, ctx->thread_index, cti, 1,
236 vlib_buffer_length_in_chain (vm, b));
240 if (PREDICT_FALSE (ctx->do_trace))
242 cnat_translation_trace_t *t;
244 t = vlib_add_trace (vm, node, b, sizeof (*t));
246 t->found_session = !rv;
247 t->created_session = created_session;
248 if (t->found_session || t->created_session)
249 clib_memcpy (&t->session, session, sizeof (t->session));
250 t->has_tr = (NULL != ct);
252 clib_memcpy (&t->tr, ct, sizeof (cnat_translation_t));
257 VLIB_NODE_FN (cnat_vip_ip4_node) (vlib_main_t * vm,
258 vlib_node_runtime_t * node,
259 vlib_frame_t * frame)
261 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
262 return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP4,
264 return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP4,
268 VLIB_NODE_FN (cnat_vip_ip6_node) (vlib_main_t * vm,
269 vlib_node_runtime_t * node,
270 vlib_frame_t * frame)
272 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
273 return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP6,
275 return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP6,
280 VLIB_REGISTER_NODE (cnat_vip_ip4_node) =
282 .name = "ip4-cnat-tx",
283 .vector_size = sizeof (u32),
284 .format_trace = format_cnat_translation_trace,
285 .type = VLIB_NODE_TYPE_INTERNAL,
287 .n_next_nodes = CNAT_TRANSLATION_N_NEXT,
290 [CNAT_TRANSLATION_NEXT_DROP] = "ip4-drop",
291 [CNAT_TRANSLATION_NEXT_LOOKUP] = "ip4-lookup",
294 VLIB_REGISTER_NODE (cnat_vip_ip6_node) =
296 .name = "ip6-cnat-tx",
297 .vector_size = sizeof (u32),
298 .format_trace = format_cnat_translation_trace,
299 .type = VLIB_NODE_TYPE_INTERNAL,
301 .n_next_nodes = CNAT_TRANSLATION_N_NEXT,
304 [CNAT_TRANSLATION_NEXT_DROP] = "ip6-drop",
305 [CNAT_TRANSLATION_NEXT_LOOKUP] = "ip6-lookup",