1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
|
/*
* 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 <vlibmemory/api.h>
#include <cnat/cnat_node.h>
#include <cnat/cnat_translation.h>
#include <vnet/dpo/load_balance.h>
#include <vnet/dpo/load_balance_map.h>
typedef struct cnat_translation_trace_t_
{
cnat_session_t session;
cnat_translation_t tr;
u32 found_session;
u32 created_session;
u32 has_tr;
} cnat_translation_trace_t;
typedef enum cnat_translation_next_t_
{
CNAT_TRANSLATION_NEXT_DROP,
CNAT_TRANSLATION_NEXT_LOOKUP,
CNAT_TRANSLATION_N_NEXT,
} cnat_translation_next_t;
vlib_node_registration_t cnat_vip_ip4_node;
vlib_node_registration_t cnat_vip_ip6_node;
static u8 *
format_cnat_translation_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_translation_trace_t *t =
va_arg (*args, cnat_translation_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,
format_cnat_translation,
&t->tr, 0);
else if (t->has_tr)
s = format (s, "tr pass: %U", format_cnat_translation,
&t->tr, 0);
else
s = format (s, "not found");
return s;
}
/* CNat sub for NAT behind a fib entry (VIP or interposed real IP) */
always_inline uword
cnat_vip_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)
{
vlib_combined_counter_main_t *cntm = &cnat_translation_counters;
cnat_main_t *cm = &cnat_main;
const cnat_translation_t *ct = NULL;
ip4_header_t *ip4 = NULL;
ip_protocol_t iproto;
ip6_header_t *ip6 = NULL;
udp_header_t *udp0;
cnat_client_t *cc;
u16 next0;
index_t cti;
int created_session = 0;
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);
}
cc = cnat_client_get (vnet_buffer (b)->ip.adj_index[VLIB_TX]);
if (iproto != IP_PROTOCOL_UDP && iproto != IP_PROTOCOL_TCP)
{
/* Dont translate & follow the fib programming */
next0 = cc->cc_parent.dpoi_next_node;
vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
goto trace;
}
ct = cnat_find_translation (cc->parent_cci,
clib_host_to_net_u16 (udp0->dst_port),
iproto);
if (!rv)
{
/* session table hit */
cnat_timestamp_update (session->value.cs_ts_index, ctx->now);
if (NULL != ct)
{
/* Translate & follow the translation given LB */
next0 = ct->ct_lb.dpoi_next_node;
vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
}
else if (session->value.flags & CNAT_SESSION_FLAG_HAS_SNAT)
{
/* The return needs DNAT, so we need an additionnal
* lookup after translation */
next0 = CNAT_TRANSLATION_NEXT_LOOKUP;
}
else
{
/* Translate & follow the fib programming */
next0 = cc->cc_parent.dpoi_next_node;
vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
}
}
else
{
if (NULL == ct)
{
/* Dont translate & Follow the fib programming */
vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
next0 = cc->cc_parent.dpoi_next_node;
goto trace;
}
/* New flow, create the sessions */
const load_balance_t *lb0;
cnat_ep_trk_t *trk0;
u32 hash_c0, bucket0;
u32 rsession_flags = 0;
const dpo_id_t *dpo0;
lb0 = load_balance_get (ct->ct_lb.dpoi_index);
if (!lb0->lb_n_buckets)
{
/* Dont translate & Follow the fib programming */
vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
next0 = cc->cc_parent.dpoi_next_node;
goto trace;
}
/* session table miss */
hash_c0 = (AF_IP4 == ctx->af ?
ip4_compute_flow_hash (ip4, lb0->lb_hash_config) :
ip6_compute_flow_hash (ip6, lb0->lb_hash_config));
bucket0 = hash_c0 & lb0->lb_n_buckets_minus_1;
dpo0 = load_balance_get_fwd_bucket (lb0, bucket0);
/* add the session */
trk0 = &ct->ct_paths[bucket0];
ip46_address_copy (&session->value.cs_ip[VLIB_TX],
&trk0->ct_ep[VLIB_TX].ce_ip.ip);
if (ip_address_is_zero (&trk0->ct_ep[VLIB_RX].ce_ip))
{
if (AF_IP4 == ctx->af)
ip46_address_set_ip4 (&session->value.cs_ip[VLIB_RX],
&ip4->src_address);
else
ip46_address_set_ip6 (&session->value.cs_ip[VLIB_RX],
&ip6->src_address);
}
else
{
/* We source NAT with the translation */
rsession_flags |= CNAT_SESSION_FLAG_HAS_SNAT;
ip46_address_copy (&session->value.cs_ip[VLIB_RX],
&trk0->ct_ep[VLIB_RX].ce_ip.ip);
}
session->value.cs_port[VLIB_TX] =
clib_host_to_net_u16 (trk0->ct_ep[VLIB_TX].ce_port);
session->value.cs_port[VLIB_RX] =
clib_host_to_net_u16 (trk0->ct_ep[VLIB_RX].ce_port);
session->value.flags = 0;
if (!session->value.cs_port[VLIB_RX])
{
u16 sport;
sport = udp0->src_port;
/* Allocate a port only if asked and if we actually sNATed */
if ((ct->flags & CNAT_TRANSLATION_FLAG_ALLOCATE_PORT)
&& (rsession_flags & CNAT_SESSION_FLAG_HAS_SNAT)) {
sport = 0; /* force allocation */
session->value.flags |= CNAT_SESSION_FLAG_ALLOC_PORT;
rv = cnat_allocate_port (cm, &sport);
if (rv)
{
vlib_node_increment_counter (vm, cnat_vip_ip4_node.index,
CNAT_ERROR_EXHAUSTED_PORTS, 1);
next0 = CNAT_TRANSLATION_NEXT_DROP;
goto trace;
}
}
session->value.cs_port[VLIB_RX] = sport;
}
session->value.cs_lbi = dpo0->dpoi_index;
cnat_client_cnt_session (cc);
cnat_session_create (session, ctx, rsession_flags);
created_session = 1;
next0 = ct->ct_lb.dpoi_next_node;
vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
}
if (AF_IP4 == ctx->af)
cnat_translation_ip4 (session, ip4, udp0);
else
cnat_translation_ip6 (session, ip6, udp0);
if (NULL != ct)
{
cti = ct - cnat_translation_pool;
vlib_increment_combined_counter (cntm, ctx->thread_index, cti, 1,
vlib_buffer_length_in_chain (vm, b));
}
trace:
if (PREDICT_FALSE (ctx->do_trace))
{
cnat_translation_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));
t->has_tr = (NULL != ct);
if (t->has_tr)
clib_memcpy (&t->tr, ct, sizeof (cnat_translation_t));
}
return next0;
}
VLIB_NODE_FN (cnat_vip_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_vip_inline, AF_IP4,
1 /* do_trace */ );
return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP4,
0 /* do_trace */ );
}
VLIB_NODE_FN (cnat_vip_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_vip_inline, AF_IP6,
1 /* do_trace */ );
return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP6,
0 /* do_trace */ );
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (cnat_vip_ip4_node) =
{
.name = "ip4-cnat-tx",
.vector_size = sizeof (u32),
.format_trace = format_cnat_translation_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = 0,
.n_next_nodes = CNAT_TRANSLATION_N_NEXT,
.next_nodes =
{
[CNAT_TRANSLATION_NEXT_DROP] = "ip4-drop",
[CNAT_TRANSLATION_NEXT_LOOKUP] = "ip4-lookup",
}
};
VLIB_REGISTER_NODE (cnat_vip_ip6_node) =
{
.name = "ip6-cnat-tx",
.vector_size = sizeof (u32),
.format_trace = format_cnat_translation_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = 0,
.n_next_nodes = CNAT_TRANSLATION_N_NEXT,
.next_nodes =
{
[CNAT_TRANSLATION_NEXT_DROP] = "ip6-drop",
[CNAT_TRANSLATION_NEXT_LOOKUP] = "ip6-lookup",
}
};
/* *INDENT-ON* */
|
