aboutsummaryrefslogtreecommitdiffstats
path: root/src/plugins/nat/det44/det44.h
blob: e576bfb65e8e13720393b26f6051da750dabc67a (plain)
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
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
/*
 * det44.h - deterministic NAT definitions
 *
 * 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.
 */

/**
 * @file
 * @brief Deterministic NAT (CGN) definitions
 */

#ifndef __included_det44_h__
#define __included_det44_h__

#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/ip/icmp46_packet.h>
#include <vnet/api_errno.h>
#include <vnet/fib/fib_source.h>
#include <vppinfra/dlist.h>
#include <vppinfra/error.h>
#include <vlibapi/api.h>
#include <vlib/log.h>
#include <vnet/fib/fib_table.h>
#include <vnet/fib/ip4_fib.h>
#include <vnet/ip/reass/ip4_sv_reass.h>

#include <nat/lib/lib.h>
#include <nat/lib/inlines.h>
#include <nat/lib/ipfix_logging.h>
#include <nat/lib/nat_proto.h>

/* Session state */
#define foreach_det44_session_state        \
  _(0, UNKNOWN, "unknown")                 \
  _(1, UDP_ACTIVE, "udp-active")           \
  _(2, TCP_SYN_SENT, "tcp-syn-sent")       \
  _(3, TCP_ESTABLISHED, "tcp-established") \
  _(4, TCP_FIN_WAIT, "tcp-fin-wait")       \
  _(5, TCP_CLOSE_WAIT, "tcp-close-wait")   \
  _(6, TCP_CLOSING, "tcp-closing")         \
  _(7, TCP_LAST_ACK, "tcp-last-ack")       \
  _(8, TCP_CLOSED, "tcp-closed")           \
  _(9, ICMP_ACTIVE, "icmp-active")

typedef enum
{
#define _(v, N, s) DET44_SESSION_##N = v,
  foreach_det44_session_state
#undef _
} det44_session_state_t;

#define DET44_SES_PER_USER 1000

typedef struct
{
  u16 identifier;
  u16 sequence;
} icmp_echo_header_t;

typedef struct
{
  u16 src_port, dst_port;
} tcp_udp_header_t;

typedef struct
{
  u32 cached_sw_if_index;
  u32 cached_ip4_address;
} det44_runtime_t;

/* deterministic session outside key */
typedef struct
{
  union
  {
    struct
    {
      ip4_address_t ext_host_addr;
      u16 ext_host_port;
      u16 out_port;
    };
    u64 as_u64;
  };
} snat_det_out_key_t;

typedef struct
{
  /* Inside network port */
  u16 in_port;
  /* Outside network address and port */
  snat_det_out_key_t out;
  /* Session state */
  u8 state;
  /* Expire timeout */
  u32 expire;
} snat_det_session_t;

typedef struct
{
  /* inside IP address range */
  ip4_address_t in_addr;
  u8 in_plen;
  /* outside IP address range */
  ip4_address_t out_addr;
  u8 out_plen;
  /* inside IP addresses / outside IP addresses */
  u32 sharing_ratio;
  /* number of ports available to internal host */
  u16 ports_per_host;
  /* session counter */
  u32 ses_num;
  /* vector of sessions */
  snat_det_session_t *sessions;
} snat_det_map_t;

typedef struct
{
  u32 sw_if_index;
  u8 flags;
} det44_interface_t;

typedef struct
{
  u32 outside_vrf_id;
  u32 inside_vrf_id;
} det44_config_t;

typedef struct
{
  u32 fib_index;
  u32 refcount;
} det44_fib_t;

typedef struct det44_main_s
{
  det44_config_t config;

  u32 outside_fib_index;
  u32 inside_fib_index;

  /* Vector of outside fibs */
  det44_fib_t *outside_fibs;

  fib_source_t fib_src_hi;
  fib_source_t fib_src_low;

  u32 out2in_node_index;
  u32 in2out_node_index;

  /* Deterministic NAT mappings */
  snat_det_map_t *det_maps;

  /* TCP MSS clamping */
  u16 mss_clamping;

  /* Protocol timeouts */
  nat_timeouts_t timeouts;

  /* Expire walk process node index */
  u32 expire_walk_node_index;

  u32 enabled;

  /* API message ID base */
  u16 msg_id_base;

  /* log class */
  vlib_log_class_t log_class;

  det44_interface_t *interfaces;

  /* convenience */
  ip4_main_t *ip4_main;
  /* required */
  vnet_main_t *vnet_main;

} det44_main_t;

extern det44_main_t det44_main;

/* logging */
#define det44_log_err(...) \
  vlib_log(VLIB_LOG_LEVEL_ERR, det44_main.log_class, __VA_ARGS__)
#define det44_log_warn(...) \
  vlib_log(VLIB_LOG_LEVEL_WARNING, det44_main.log_class, __VA_ARGS__)
#define det44_log_notice(...) \
  vlib_log(VLIB_LOG_LEVEL_NOTICE, det44_main.log_class, __VA_ARGS__)
#define det44_log_info(...) \
  vlib_log(VLIB_LOG_LEVEL_INFO, det44_main.log_class, __VA_ARGS__)
#define det44_log_debug(...)\
  vlib_log(VLIB_LOG_LEVEL_DEBUG, det44_main.log_class, __VA_ARGS__)

/* Deterministic NAT interface flags */
#define DET44_INTERFACE_FLAG_IS_INSIDE 1
#define DET44_INTERFACE_FLAG_IS_OUTSIDE 2

/** \brief Check if Deterministic NAT interface is inside.
    @param i Deterministic NAT interface
    @return 1 if inside interface
*/
#define det44_interface_is_inside(i) i->flags & DET44_INTERFACE_FLAG_IS_INSIDE

/** \brief Check if Deterministic NAT interface is outside.
    @param i Deterministic NAT interface
    @return 1 if outside interface
*/
#define det44_interface_is_outside(i) i->flags & DET44_INTERFACE_FLAG_IS_OUTSIDE

static_always_inline u8
plugin_enabled ()
{
  det44_main_t *dm = &det44_main;
  return dm->enabled;
}

extern vlib_node_registration_t det44_in2out_node;
extern vlib_node_registration_t det44_out2in_node;

int det44_plugin_enable (det44_config_t);
int det44_plugin_disable ();

int det44_interface_add_del (u32 sw_if_index, u8 is_inside, int is_del);

int det44_set_timeouts (nat_timeouts_t * timeouts);
nat_timeouts_t det44_get_timeouts ();
void det44_reset_timeouts ();

/* format functions */
format_function_t format_det_map_ses;

int snat_det_add_map (ip4_address_t * in_addr, u8 in_plen,
		      ip4_address_t * out_addr, u8 out_plen, int is_add);

/* icmp session match functions */
u32 icmp_match_out2in_det (vlib_node_runtime_t * node,
			   u32 thread_index, vlib_buffer_t * b0,
			   ip4_header_t * ip0, ip4_address_t * addr,
			   u16 * port, u32 * fib_index,
			   nat_protocol_t * proto, void *d, void *e,
			   u8 * dont_translate);
u32 icmp_match_in2out_det (vlib_node_runtime_t * node,
			   u32 thread_index, vlib_buffer_t * b0,
			   ip4_header_t * ip0, ip4_address_t * addr,
			   u16 * port, u32 * fib_index,
			   nat_protocol_t * proto, void *d, void *e,
			   u8 * dont_translate);
u32 det44_icmp_in2out (vlib_buffer_t * b0, ip4_header_t * ip0,
		       icmp46_header_t * icmp0, u32 sw_if_index0,
		       u32 rx_fib_index0, vlib_node_runtime_t * node,
		       u32 next0, u32 thread_index, void *d, void *e);
u32 det44_icmp_out2in (vlib_buffer_t * b0, ip4_header_t * ip0,
		       icmp46_header_t * icmp0, u32 sw_if_index0,
		       u32 rx_fib_index0, vlib_node_runtime_t * node,
		       u32 next0, u32 thread_index, void *d, void *e);

static_always_inline int
is_addr_in_net (ip4_address_t * addr, ip4_address_t * net, u8 plen)
{
  if (net->as_u32 == (addr->as_u32 & ip4_main.fib_masks[plen]))
    return 1;
  return 0;
}

static_always_inline snat_det_map_t *
snat_det_map_by_user (ip4_address_t * user_addr)
{
  det44_main_t *dm = &det44_main;
  snat_det_map_t *mp;
  pool_foreach (mp, dm->det_maps)
   {
    if (is_addr_in_net(user_addr, &mp->in_addr, mp->in_plen))
      return mp;
  }
  return 0;
}

static_always_inline snat_det_map_t *
snat_det_map_by_out (ip4_address_t * out_addr)
{
  det44_main_t *dm = &det44_main;
  snat_det_map_t *mp;
  pool_foreach (mp, dm->det_maps)
   {
    if (is_addr_in_net(out_addr, &mp->out_addr, mp->out_plen))
      return mp;
  }
  return 0;
}

static_always_inline void
snat_det_forward (snat_det_map_t * dm, ip4_address_t * in_addr,
		  ip4_address_t * out_addr, u16 * lo_port)
{
  u32 in_offset, out_offset;

  in_offset = clib_net_to_host_u32 (in_addr->as_u32) -
    clib_net_to_host_u32 (dm->in_addr.as_u32);
  out_offset = in_offset / dm->sharing_ratio;
  out_addr->as_u32 =
    clib_host_to_net_u32 (clib_net_to_host_u32 (dm->out_addr.as_u32) +
			  out_offset);
  *lo_port = 1024 + dm->ports_per_host * (in_offset % dm->sharing_ratio);
}

static_always_inline void
snat_det_reverse (snat_det_map_t * dm, ip4_address_t * out_addr, u16 out_port,
		  ip4_address_t * in_addr)
{
  u32 in_offset1, in_offset2, out_offset;

  out_offset = clib_net_to_host_u32 (out_addr->as_u32) -
    clib_net_to_host_u32 (dm->out_addr.as_u32);
  in_offset1 = out_offset * dm->sharing_ratio;
  in_offset2 = (out_port - 1024) / dm->ports_per_host;
  in_addr->as_u32 =
    clib_host_to_net_u32 (clib_net_to_host_u32 (dm->in_addr.as_u32) +
			  in_offset1 + in_offset2);
}

static_always_inline u32
snat_det_user_ses_offset (ip4_address_t * addr, u8 plen)
{
  return (clib_net_to_host_u32 (addr->as_u32) & pow2_mask (32 - plen)) *
    DET44_SES_PER_USER;
}

static_always_inline snat_det_session_t *
snat_det_get_ses_by_out (snat_det_map_t * dm, ip4_address_t * in_addr,
			 u64 out_key)
{
  u32 user_offset;
  u16 i;

  user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen);
  for (i = 0; i < DET44_SES_PER_USER; i++)
    {
      if (dm->sessions[i + user_offset].out.as_u64 == out_key)
	return &dm->sessions[i + user_offset];
    }

  return 0;
}

static_always_inline snat_det_session_t *
snat_det_find_ses_by_in (snat_det_map_t * dm, ip4_address_t * in_addr,
			 u16 in_port, snat_det_out_key_t out_key)
{
  snat_det_session_t *ses;
  u32 user_offset;
  u16 i;

  user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen);
  for (i = 0; i < DET44_SES_PER_USER; i++)
    {
      ses = &dm->sessions[i + user_offset];
      if (ses->in_port == in_port &&
	  ses->out.ext_host_addr.as_u32 == out_key.ext_host_addr.as_u32 &&
	  ses->out.ext_host_port == out_key.ext_host_port)
	return &dm->sessions[i + user_offset];
    }

  return 0;
}

static_always_inline snat_det_session_t *
snat_det_ses_create (u32 thread_index, snat_det_map_t * dm,
		     ip4_address_t * in_addr, u16 in_port,
		     snat_det_out_key_t * out)
{
  u32 user_offset;
  u16 i;

  user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen);

  for (i = 0; i < DET44_SES_PER_USER; i++)
    {
      if (!dm->sessions[i + user_offset].in_port)
	{
	  if (clib_atomic_bool_cmp_and_swap
	      (&dm->sessions[i + user_offset].in_port, 0, in_port))
	    {
	      dm->sessions[i + user_offset].out.as_u64 = out->as_u64;
	      dm->sessions[i + user_offset].state = DET44_SESSION_UNKNOWN;
	      dm->sessions[i + user_offset].expire = 0;
	      clib_atomic_add_fetch (&dm->ses_num, 1);
	      return &dm->sessions[i + user_offset];
	    }
	}
    }

  nat_ipfix_logging_max_entries_per_user (thread_index,
					  DET44_SES_PER_USER,
					  in_addr->as_u32);
  return 0;
}

static_always_inline void
snat_det_ses_close (snat_det_map_t * dm, snat_det_session_t * ses)
{
  if (clib_atomic_bool_cmp_and_swap (&ses->in_port, ses->in_port, 0))
    {
      ses->out.as_u64 = 0;
      clib_atomic_add_fetch (&dm->ses_num, -1);
    }
}

clib_error_t *det44_api_hookup (vlib_main_t * vm);

#endif /* __included_det44_h__ */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */