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>
19 #include <cnat/cnat_inline.h>
20 #include <cnat/cnat_src_policy.h>
21 #include <cnat/cnat_snat_policy.h>
23 #include <vnet/dpo/load_balance.h>
24 #include <vnet/dpo/load_balance_map.h>
26 #include <vnet/ip/ip4_inlines.h>
27 #include <vnet/ip/ip6_inlines.h>
29 typedef enum cnat_feature_next_
31 CNAT_FEATURE_NEXT_DROP,
33 } cnat_feature_next_t;
35 vlib_node_registration_t cnat_input_feature_ip4_node;
36 vlib_node_registration_t cnat_input_feature_ip6_node;
37 vlib_node_registration_t cnat_output_feature_ip4_node;
38 vlib_node_registration_t cnat_output_feature_ip6_node;
41 cnat_input_feature_fn (vlib_main_t *vm, vlib_node_runtime_t *node,
42 vlib_buffer_t *b, cnat_node_ctx_t *ctx,
43 int session_not_found, cnat_session_t *session)
45 vlib_combined_counter_main_t *cntm = &cnat_translation_counters;
46 const cnat_translation_t *ct = NULL;
47 ip4_header_t *ip4 = NULL;
49 ip6_header_t *ip6 = NULL;
56 /* By default follow arc default next */
57 vnet_feature_next (&next0, b);
59 if (AF_IP4 == ctx->af)
61 ip4 = vlib_buffer_get_current (b);
62 iproto = ip4->protocol;
63 udp0 = (udp_header_t *) (ip4 + 1);
64 cc = cnat_client_ip4_find (
65 &ip4->dst_address); /* TODO do this only if no session? */
69 ip6 = vlib_buffer_get_current (b);
70 iproto = ip6->protocol;
71 udp0 = (udp_header_t *) (ip6 + 1);
72 cc = cnat_client_ip6_find (&ip6->dst_address); /* TODO: same as above */
75 /* Wrong session key */
76 if (session->key.cs_proto == 0)
79 if (!session_not_found)
80 /* session table hit */
81 cnat_timestamp_update (session->value.cs_ts_index, ctx->now);
83 goto trace; /* dst address is not a vip */
86 ct = cnat_find_translation (
87 cc->parent_cci, clib_host_to_net_u16 (udp0->dst_port), iproto);
90 /* TODO: create identity session to avoid slowpath ? */
93 /* New flow, create the sessions */
94 const load_balance_t *lb0;
96 u32 rsession_flags = CNAT_SESSION_FLAG_NO_CLIENT;
99 lb0 = load_balance_get (ct->ct_lb.dpoi_index);
100 if (!lb0->lb_n_buckets)
101 /* Can't translate TODO: should drop / reject? */
104 /* session table miss */
105 trk0 = cnat_load_balance (ct, ctx->af, ip4, ip6, &dpoi_index);
106 if (PREDICT_FALSE (NULL == trk0))
108 /* Dont translate & Follow the fib programming */
109 vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
110 next0 = cc->cc_parent.dpoi_next_node;
114 ip46_address_copy (&session->value.cs_ip[VLIB_TX],
115 &trk0->ct_ep[VLIB_TX].ce_ip.ip);
117 /* never source nat in this node */
118 if (AF_IP4 == ctx->af)
119 ip46_address_set_ip4 (&session->value.cs_ip[VLIB_RX],
122 ip46_address_set_ip6 (&session->value.cs_ip[VLIB_RX],
125 session->value.cs_port[VLIB_TX] =
126 clib_host_to_net_u16 (trk0->ct_ep[VLIB_TX].ce_port);
127 session->value.cs_port[VLIB_RX] = udp0->src_port;
128 session->value.flags = 0;
130 if (trk0->ct_flags & CNAT_TRK_FLAG_NO_NAT)
132 const dpo_id_t *dpo0;
133 const load_balance_t *lb1;
135 lb1 = load_balance_get (trk0->ct_dpo.dpoi_index);
136 /* Assume backend has exactly one item in LB */
137 dpo0 = load_balance_get_bucket_i (lb1, 0);
139 session->value.dpoi_next_node = dpo0->dpoi_next_node;
140 session->value.cs_lbi = dpo0->dpoi_index;
141 session->value.flags = CNAT_SESSION_FLAG_NO_NAT;
144 /* refcnt session in current client */
145 cnat_client_cnt_session (cc);
146 cnat_session_create (session, ctx, CNAT_LOCATION_OUTPUT, rsession_flags);
147 trace_flags |= CNAT_TRACE_SESSION_CREATED;
150 if (session->value.flags & CNAT_SESSION_FLAG_NO_NAT)
152 /* If we don't translate, directly do the lookup & bypass arc */
153 next0 = session->value.dpoi_next_node;
154 vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
158 if (AF_IP4 == ctx->af)
159 cnat_translation_ip4 (session, ip4, udp0);
161 cnat_translation_ip6 (session, ip6, udp0);
165 cti = ct - cnat_translation_pool;
166 vlib_increment_combined_counter (cntm, ctx->thread_index, cti, 1,
167 vlib_buffer_length_in_chain (vm, b));
171 if (PREDICT_FALSE (ctx->do_trace))
173 trace_flags |= session_not_found ? 0 : CNAT_TRACE_SESSION_FOUND;
174 cnat_add_trace (vm, node, b, session, ct, trace_flags);
179 VLIB_NODE_FN (cnat_input_feature_ip4_node)
180 (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
182 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
183 return cnat_node_inline (vm, node, frame, cnat_input_feature_fn, AF_IP4,
184 CNAT_LOCATION_INPUT, 1 /* do_trace */);
185 return cnat_node_inline (vm, node, frame, cnat_input_feature_fn, AF_IP4,
186 CNAT_LOCATION_INPUT, 0 /* do_trace */);
189 VLIB_REGISTER_NODE (cnat_input_feature_ip4_node) = {
190 .name = "cnat-input-ip4",
191 .vector_size = sizeof (u32),
192 .format_trace = format_cnat_trace,
193 .type = VLIB_NODE_TYPE_INTERNAL,
194 .n_errors = CNAT_N_ERROR,
195 .error_strings = cnat_error_strings,
196 .sibling_of = "ip4-lookup",
199 VNET_FEATURE_INIT (cnat_in_ip4_feature, static) = {
200 .arc_name = "ip4-unicast",
201 .node_name = "cnat-input-ip4",
202 .runs_before = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
205 VLIB_NODE_FN (cnat_input_feature_ip6_node)
206 (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
208 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
209 return cnat_node_inline (vm, node, frame, cnat_input_feature_fn, AF_IP6,
210 CNAT_LOCATION_INPUT, 1 /* do_trace */);
211 return cnat_node_inline (vm, node, frame, cnat_input_feature_fn, AF_IP6,
212 CNAT_LOCATION_INPUT, 0 /* do_trace */);
215 VLIB_REGISTER_NODE (cnat_input_feature_ip6_node) = {
216 .name = "cnat-input-ip6",
217 .vector_size = sizeof (u32),
218 .format_trace = format_cnat_trace,
219 .type = VLIB_NODE_TYPE_INTERNAL,
220 .n_errors = CNAT_N_ERROR,
221 .error_strings = cnat_error_strings,
222 .sibling_of = "ip6-lookup",
225 VNET_FEATURE_INIT (cnat_in_ip6_feature, static) = {
226 .arc_name = "ip6-unicast",
227 .node_name = "cnat-input-ip6",
228 .runs_before = VNET_FEATURES ("acl-plugin-in-ip6-fa"),
231 /* output feature node, creates snat sessions when required and
232 * translates back for existing sessions */
234 cnat_output_feature_fn (vlib_main_t *vm, vlib_node_runtime_t *node,
235 vlib_buffer_t *b, cnat_node_ctx_t *ctx,
236 int session_not_found, cnat_session_t *session)
238 cnat_snat_policy_main_t *cpm = &cnat_snat_policy_main;
239 ip4_header_t *ip4 = NULL;
240 ip_protocol_t iproto;
241 ip6_header_t *ip6 = NULL;
250 /* By default follow arc default next */
251 vnet_feature_next (&next0, b);
252 iph_offset = vnet_buffer (b)->ip.save_rewrite_length;
254 if (AF_IP4 == ctx->af)
256 ip4 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b) + iph_offset);
257 iproto = ip4->protocol;
258 udp0 = (udp_header_t *) (ip4 + 1);
262 ip6 = (ip6_header_t *) ((u8 *) vlib_buffer_get_current (b) + iph_offset);
263 iproto = ip6->protocol;
264 udp0 = (udp_header_t *) (ip6 + 1);
267 /* Wrong session key */
268 if (session->key.cs_proto == 0)
271 if (!session_not_found)
273 /* session table hit */
274 cnat_timestamp_update (session->value.cs_ts_index, ctx->now);
276 else if (!cpm->snat_policy)
280 do_snat = cpm->snat_policy (b, session);
284 if (AF_IP4 == ctx->af)
286 if (ip_address_is_zero (&cpm->snat_ip4.ce_ip))
289 ip46_address_set_ip4 (&session->value.cs_ip[VLIB_RX],
290 &ip_addr_v4 (&cpm->snat_ip4.ce_ip));
291 ip46_address_set_ip4 (&session->value.cs_ip[VLIB_TX],
296 if (ip_address_is_zero (&cpm->snat_ip6.ce_ip))
299 ip46_address_set_ip6 (&session->value.cs_ip[VLIB_RX],
300 &ip_addr_v6 (&cpm->snat_ip6.ce_ip));
301 ip46_address_set_ip6 (&session->value.cs_ip[VLIB_TX],
305 rv = cnat_allocate_port (&sport, iproto);
308 vlib_node_increment_counter (vm, cnat_output_feature_ip6_node.index,
309 CNAT_ERROR_EXHAUSTED_PORTS, 1);
310 next0 = CNAT_FEATURE_NEXT_DROP;
313 session->value.cs_port[VLIB_RX] = sport;
314 session->value.cs_port[VLIB_TX] = sport;
315 if (iproto == IP_PROTOCOL_TCP || iproto == IP_PROTOCOL_UDP)
316 session->value.cs_port[VLIB_TX] = udp0->dst_port;
318 session->value.cs_lbi = INDEX_INVALID;
319 session->value.flags =
320 CNAT_SESSION_FLAG_NO_CLIENT | CNAT_SESSION_FLAG_ALLOC_PORT;
322 trace_flags |= CNAT_TRACE_SESSION_CREATED;
323 cnat_session_create (session, ctx, CNAT_LOCATION_INPUT,
324 CNAT_SESSION_FLAG_NO_CLIENT);
327 if (AF_IP4 == ctx->af)
328 cnat_translation_ip4 (session, ip4, udp0);
330 cnat_translation_ip6 (session, ip6, udp0);
333 if (PREDICT_FALSE (ctx->do_trace))
335 trace_flags |= do_snat ? 0 : CNAT_TRACE_NO_NAT;
336 trace_flags |= session_not_found ? 0 : CNAT_TRACE_SESSION_FOUND;
337 cnat_add_trace (vm, node, b, session, NULL, trace_flags);
342 VLIB_NODE_FN (cnat_output_feature_ip4_node)
343 (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
345 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
346 return cnat_node_inline (vm, node, frame, cnat_output_feature_fn, AF_IP4,
347 CNAT_LOCATION_OUTPUT, 1 /* do_trace */);
348 return cnat_node_inline (vm, node, frame, cnat_output_feature_fn, AF_IP4,
349 CNAT_LOCATION_OUTPUT, 0 /* do_trace */);
352 VLIB_REGISTER_NODE (cnat_output_feature_ip4_node) = {
353 .name = "cnat-output-ip4",
354 .vector_size = sizeof (u32),
355 .format_trace = format_cnat_trace,
356 .type = VLIB_NODE_TYPE_INTERNAL,
357 .n_errors = CNAT_N_ERROR,
358 .error_strings = cnat_error_strings,
359 .n_next_nodes = CNAT_FEATURE_N_NEXT,
361 [CNAT_FEATURE_NEXT_DROP] = "error-drop",
365 VNET_FEATURE_INIT (cnat_out_ip4_feature, static) = {
366 .arc_name = "ip4-output",
367 .node_name = "cnat-output-ip4",
368 .runs_before = VNET_FEATURES ("gso-ip4"),
369 .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
372 VLIB_NODE_FN (cnat_output_feature_ip6_node)
373 (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
375 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
376 return cnat_node_inline (vm, node, frame, cnat_output_feature_fn, AF_IP6,
377 CNAT_LOCATION_OUTPUT, 1 /* do_trace */);
378 return cnat_node_inline (vm, node, frame, cnat_output_feature_fn, AF_IP6,
379 CNAT_LOCATION_OUTPUT, 0 /* do_trace */);
382 VLIB_REGISTER_NODE (cnat_output_feature_ip6_node) = {
383 .name = "cnat-output-ip6",
384 .vector_size = sizeof (u32),
385 .format_trace = format_cnat_trace,
386 .type = VLIB_NODE_TYPE_INTERNAL,
387 .n_errors = CNAT_N_ERROR,
388 .error_strings = cnat_error_strings,
389 .n_next_nodes = CNAT_FEATURE_N_NEXT,
391 [CNAT_FEATURE_NEXT_DROP] = "error-drop",
395 VNET_FEATURE_INIT (cnat_out_ip6_feature, static) = {
396 .arc_name = "ip6-output",
397 .node_name = "cnat-output-ip6",
398 .runs_before = VNET_FEATURES ("gso-ip6"),
399 .runs_after = VNET_FEATURES ("acl-plugin-out-ip6-fa"),
403 * fd.io coding-style-patch-verification: ON
406 * eval: (c-set-style "gnu")