aboutsummaryrefslogtreecommitdiffstats
path: root/src/vnet/ipsec/esp.h
blob: d24b5ea41025002a6537b4aff47e4fa72598de7b (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
/*
 * Copyright (c) 2015 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.
 */
#ifndef __ESP_H__
#define __ESP_H__

#include <vnet/ip/ip.h>
#include <vnet/crypto/crypto.h>
#include <vnet/ipsec/ipsec.h>

typedef struct
{
  union
  {
    u32 spi;
    u8 spi_bytes[4];
  };
  u32 seq;
  u8 data[0];
} esp_header_t;

typedef struct
{
  u8 pad_length;
  u8 next_header;
} esp_footer_t;

/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
  ip4_header_t ip4;
  esp_header_t esp;
}) ip4_and_esp_header_t;
/* *INDENT-ON* */

/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
  ip4_header_t ip4;
  udp_header_t udp;
  esp_header_t esp;
}) ip4_and_udp_and_esp_header_t;
/* *INDENT-ON* */

/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
  ip6_header_t ip6;
  esp_header_t esp;
}) ip6_and_esp_header_t;
/* *INDENT-ON* */

/**
 * AES GCM Additional Authentication data
 */
typedef struct esp_aead_t_
{
  /**
   * for GCM: when using ESN it's:
   *   SPI, seq-hi, seg-low
   * else
   *   SPI, seq-low
   */
  u32 data[3];
} __clib_packed esp_aead_t;

#define ESP_SEQ_MAX		(4294967295UL)
#define ESP_MAX_BLOCK_SIZE	(16)
#define ESP_MAX_IV_SIZE		(16)
#define ESP_MAX_ICV_SIZE	(32)

u8 *format_esp_header (u8 * s, va_list * args);

/* TODO seq increment should be atomic to be accessed by multiple workers */
always_inline int
esp_seq_advance (ipsec_sa_t * sa)
{
  if (PREDICT_TRUE (ipsec_sa_is_set_USE_ESN (sa)))
    {
      if (PREDICT_FALSE (sa->seq == ESP_SEQ_MAX))
	{
	  if (PREDICT_FALSE (ipsec_sa_is_set_USE_ANTI_REPLAY (sa) &&
			     sa->seq_hi == ESP_SEQ_MAX))
	    return 1;
	  sa->seq_hi++;
	}
      sa->seq++;
    }
  else
    {
      if (PREDICT_FALSE (ipsec_sa_is_set_USE_ANTI_REPLAY (sa) &&
			 sa->seq == ESP_SEQ_MAX))
	return 1;
      sa->seq++;
    }

  return 0;
}

always_inline u16
esp_aad_fill (u8 * data, const esp_header_t * esp, const ipsec_sa_t * sa)
{
  esp_aead_t *aad;

  aad = (esp_aead_t *) data;
  aad->data[0] = esp->spi;

  if (ipsec_sa_is_set_USE_ESN (sa))
    {
      /* SPI, seq-hi, seq-low */
      aad->data[1] = (u32) clib_host_to_net_u32 (sa->seq_hi);
      aad->data[2] = esp->seq;
      return 12;
    }
  else
    {
      /* SPI, seq-low */
      aad->data[1] = esp->seq;
      return 8;
    }
}

/* Special case to drop or hand off packets for sync/async modes.
 *
 * Different than sync mode, async mode only enqueue drop or hand-off packets
 * to next nodes.
 */
always_inline void
esp_set_next_index (int is_async, u32 * from, u16 * nexts, u32 bi,
		    u16 * drop_index, u16 drop_next, u16 * next)
{
  if (is_async)
    {
      from[*drop_index] = bi;
      nexts[*drop_index] = drop_next;
      *drop_index += 1;
    }
  else
    next[0] = drop_next;
}

/* when submitting a frame is failed, drop all buffers in the frame */
always_inline void
esp_async_recycle_failed_submit (vnet_crypto_async_frame_t * f,
				 vlib_buffer_t ** b, u32 * from, u16 * nexts,
				 u16 * n_dropped, u16 drop_next_index,
				 vlib_error_t err)
{
  u32 n_drop = f->n_elts;
  u32 *bi = f->buffer_indices;
  b -= n_drop;
  while (n_drop--)
    {
      b[0]->error = err;
      esp_set_next_index (1, from, nexts, bi[0], n_dropped, drop_next_index,
			  NULL);
      bi++;
      b++;
    }
  vnet_crypto_async_reset_frame (f);
}

/**
 * The post data structure to for esp_encrypt/decrypt_inline to write to
 * vib_buffer_t opaque unused field, and for post nodes to pick up after
 * dequeue.
 **/
typedef struct
{
  union
  {
    struct
    {
      u8 icv_sz;
      u8 iv_sz;
      ipsec_sa_flags_t flags;
      u32 sa_index;
    };
    u64 sa_data;
  };

  u32 seq;
  i16 current_data;
  i16 current_length;
  u16 hdr_sz;
  u16 is_chain;
  u32 protect_index;
} esp_decrypt_packet_data_t;

STATIC_ASSERT_SIZEOF (esp_decrypt_packet_data_t, 3 * sizeof (u64));

/* we are forced to store the decrypt post data into 2 separate places -
   vlib_opaque and opaque2. */
typedef struct
{
  vlib_buffer_t *lb;
  u32 free_buffer_index;
  u8 icv_removed;
} esp_decrypt_packet_data2_t;

typedef union
{
  u16 next_index;
  esp_decrypt_packet_data_t decrypt_data;
} esp_post_data_t;

STATIC_ASSERT (sizeof (esp_post_data_t) <=
	       STRUCT_SIZE_OF (vnet_buffer_opaque_t, unused),
	       "Custom meta-data too large for vnet_buffer_opaque_t");

#define esp_post_data(b) \
    ((esp_post_data_t *)((u8 *)((b)->opaque) \
        + STRUCT_OFFSET_OF (vnet_buffer_opaque_t, unused)))

STATIC_ASSERT (sizeof (esp_decrypt_packet_data2_t) <=
	       STRUCT_SIZE_OF (vnet_buffer_opaque2_t, unused),
	       "Custom meta-data too large for vnet_buffer_opaque2_t");

#define esp_post_data2(b) \
    ((esp_decrypt_packet_data2_t *)((u8 *)((b)->opaque2) \
        + STRUCT_OFFSET_OF (vnet_buffer_opaque2_t, unused)))

typedef struct
{
  /* esp post node index for async crypto */
  u32 esp4_post_next;
  u32 esp6_post_next;
  u32 esp4_tun_post_next;
  u32 esp6_tun_post_next;
  u32 esp_mpls_tun_post_next;
} esp_async_post_next_t;

extern esp_async_post_next_t esp_encrypt_async_next;
extern esp_async_post_next_t esp_decrypt_async_next;

#endif /* __ESP_H__ */

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