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Vector Packet Processing
esp_encrypt.c
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1 /*
2  * esp_encrypt.c : IPSec ESP encrypt node
3  *
4  * Copyright (c) 2015 Cisco and/or its affiliates.
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at:
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 
18 #include <vnet/vnet.h>
19 #include <vnet/api_errno.h>
20 #include <vnet/ip/ip.h>
21 
22 #include <vnet/ipsec/ipsec.h>
23 #include <vnet/ipsec/esp.h>
24 
25 #define ESP_SEQ_MAX (4294967295UL)
26 
27 #define foreach_esp_encrypt_next \
28 _(DROP, "error-drop") \
29 _(IP4_INPUT, "ip4-input") \
30 _(IP6_INPUT, "ip6-input") \
31 _(INTERFACE_OUTPUT, "interface-output")
32 
33 #define _(v, s) ESP_ENCRYPT_NEXT_##v,
34 typedef enum {
36 #undef _
39 
40 #define foreach_esp_encrypt_error \
41  _(RX_PKTS, "ESP pkts received") \
42  _(NO_BUFFER, "No buffer (packet dropped)") \
43  _(DECRYPTION_FAILED, "ESP encryption failed") \
44  _(SEQ_CYCLED, "sequence number cycled")
45 
46 
47 typedef enum {
48 #define _(sym,str) ESP_ENCRYPT_ERROR_##sym,
50 #undef _
53 
54 static char * esp_encrypt_error_strings[] = {
55 #define _(sym,string) string,
57 #undef _
58 };
59 
61 
62 typedef struct {
68 
69 /* packet trace format function */
70 static u8 * format_esp_encrypt_trace (u8 * s, va_list * args)
71 {
72  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
73  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
74  esp_encrypt_trace_t * t = va_arg (*args, esp_encrypt_trace_t *);
75 
76  s = format (s, "esp: spi %u seq %u crypto %U integrity %U",
77  t->spi, t->seq,
80  return s;
81 }
82 
83 always_inline void
85  u8 * in,
86  u8 * out,
87  size_t in_len,
88  u8 * key,
89  u8 * iv)
90 {
91  esp_main_t * em = &esp_main;
92  u32 cpu_index = os_get_cpu_number();
93  EVP_CIPHER_CTX * ctx = &(em->per_thread_data[cpu_index].encrypt_ctx);
94  const EVP_CIPHER * cipher = NULL;
95  int out_len;
96 
98 
99  if (PREDICT_FALSE(em->esp_crypto_algs[alg].type == IPSEC_CRYPTO_ALG_NONE))
100  return;
101 
102  if (PREDICT_FALSE(alg != em->per_thread_data[cpu_index].last_encrypt_alg)) {
103  cipher = em->esp_crypto_algs[alg].type;
104  em->per_thread_data[cpu_index].last_encrypt_alg = alg;
105  }
106 
107  EVP_EncryptInit_ex(ctx, cipher, NULL, key, iv);
108 
109  EVP_EncryptUpdate(ctx, out, &out_len, in, in_len);
110  EVP_EncryptFinal_ex(ctx, out + out_len, &out_len);
111 }
112 
113 always_inline int
115 {
116  if (PREDICT_TRUE(sa->use_esn))
117  {
118  if (PREDICT_FALSE(sa->seq == ESP_SEQ_MAX))
119  {
120  if (PREDICT_FALSE(sa->use_anti_replay && sa->seq_hi == ESP_SEQ_MAX))
121  return 1;
122  sa->seq_hi++;
123  }
124  sa->seq++;
125  }
126  else
127  {
128  if (PREDICT_FALSE(sa->use_anti_replay && sa->seq == ESP_SEQ_MAX))
129  return 1;
130  sa->seq++;
131  }
132 
133  return 0;
134 }
135 
136 static uword
138  vlib_node_runtime_t * node,
139  vlib_frame_t * from_frame)
140 {
141  u32 n_left_from, *from, * to_next = 0, next_index;
142  from = vlib_frame_vector_args (from_frame);
143  n_left_from = from_frame->n_vectors;
144  ipsec_main_t *im = &ipsec_main;
145  u32 * recycle = 0;
146  u32 cpu_index = os_get_cpu_number();
147  u32 * empty_buffers = im->empty_buffers[cpu_index];
148 
150 
151  if (PREDICT_FALSE(vec_len (empty_buffers) < n_left_from)){
153  ESP_ENCRYPT_ERROR_NO_BUFFER, n_left_from);
154  clib_warning("no enough empty buffers. discarding frame");
155  goto free_buffers_and_exit;
156  }
157 
158  next_index = node->cached_next_index;
159 
160  while (n_left_from > 0)
161  {
162  u32 n_left_to_next;
163 
164  vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
165 
166  while (n_left_from > 0 && n_left_to_next > 0)
167  {
168  u32 i_bi0, o_bi0, next0;
169  vlib_buffer_t * i_b0, *o_b0 = 0;
170  u32 sa_index0;
171  ipsec_sa_t * sa0;
172  ip4_and_esp_header_t * ih0, * oh0 = 0;
173  ip6_and_esp_header_t * ih6_0, * oh6_0 = 0;
174  uword last_empty_buffer;
175  esp_header_t * o_esp0;
176  esp_footer_t *f0;
177  u8 is_ipv6;
178  u8 ip_hdr_size;
179  u8 next_hdr_type;
180 
181  i_bi0 = from[0];
182  from += 1;
183  n_left_from -= 1;
184  n_left_to_next -= 1;
185 
186  next0 = ESP_ENCRYPT_NEXT_DROP;
187 
188  i_b0 = vlib_get_buffer (vm, i_bi0);
189  sa_index0 = vnet_buffer(i_b0)->output_features.ipsec_sad_index;
190  sa0 = pool_elt_at_index(im->sad, sa_index0);
191 
192  if (PREDICT_FALSE(esp_seq_advance(sa0)))
193  {
194  clib_warning("sequence number counter has cycled SPI %u", sa0->spi);
196  ESP_ENCRYPT_ERROR_SEQ_CYCLED, 1);
197  //TODO: rekey SA
198  o_bi0 = i_bi0;
199  goto trace;
200  }
201 
202  /* grab free buffer */
203  last_empty_buffer = vec_len (empty_buffers) - 1;
204  o_bi0 = empty_buffers[last_empty_buffer];
205  o_b0 = vlib_get_buffer (vm, o_bi0);
206  o_b0->current_data = sizeof(ethernet_header_t);
207  ih0 = vlib_buffer_get_current (i_b0);
208  vlib_prefetch_buffer_with_index (vm, empty_buffers[last_empty_buffer-1], STORE);
209  _vec_len (empty_buffers) = last_empty_buffer;
210  to_next[0] = o_bi0;
211  to_next += 1;
212 
213  /* add old buffer to the recycle list */
214  vec_add1(recycle, i_bi0);
215 
216  /* is ipv6 */
217  if (PREDICT_FALSE((ih0->ip4.ip_version_and_header_length & 0xF0 ) == 0x60))
218  {
219  is_ipv6 = 1;
220  ih6_0 = vlib_buffer_get_current (i_b0);
221  ip_hdr_size = sizeof(ip6_header_t);
222  next_hdr_type = IP_PROTOCOL_IPV6;
223  oh6_0 = vlib_buffer_get_current (o_b0);
224  o_esp0 = vlib_buffer_get_current (o_b0) + sizeof(ip6_header_t);
225 
226  oh6_0->ip6.ip_version_traffic_class_and_flow_label =
227  ih6_0->ip6.ip_version_traffic_class_and_flow_label;
228  oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_ESP;
229  oh6_0->ip6.hop_limit = 254;
230  oh6_0->esp.spi = clib_net_to_host_u32(sa0->spi);
231  oh6_0->esp.seq = clib_net_to_host_u32(sa0->seq);
232  }
233  else
234  {
235  is_ipv6 = 0;
236  ip_hdr_size = sizeof(ip4_header_t);
237  next_hdr_type = IP_PROTOCOL_IP_IN_IP;
238  oh0 = vlib_buffer_get_current (o_b0);
239  o_esp0 = vlib_buffer_get_current (o_b0) + sizeof(ip4_header_t);
240 
241  oh0->ip4.ip_version_and_header_length = 0x45;
242  oh0->ip4.tos = ih0->ip4.tos;
243  oh0->ip4.fragment_id = 0;
244  oh0->ip4.flags_and_fragment_offset = 0;
245  oh0->ip4.ttl = 254;
246  oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
247  oh0->esp.spi = clib_net_to_host_u32(sa0->spi);
248  oh0->esp.seq = clib_net_to_host_u32(sa0->seq);
249  }
250 
251  if (PREDICT_TRUE(sa0->is_tunnel && !sa0->is_tunnel_ip6))
252  {
253  oh0->ip4.src_address.as_u32 = sa0->tunnel_src_addr.ip4.as_u32;
254  oh0->ip4.dst_address.as_u32 = sa0->tunnel_dst_addr.ip4.as_u32;
255 
256  /* in tunnel mode send it back to FIB */
257  next0 = ESP_ENCRYPT_NEXT_IP4_INPUT;
258  vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32)~0;
259  }
260  else if(sa0->is_tunnel && sa0->is_tunnel_ip6)
261  {
262  oh6_0->ip6.src_address.as_u64[0] = sa0->tunnel_src_addr.ip6.as_u64[0];
263  oh6_0->ip6.src_address.as_u64[1] = sa0->tunnel_src_addr.ip6.as_u64[1];
264  oh6_0->ip6.dst_address.as_u64[0] = sa0->tunnel_dst_addr.ip6.as_u64[0];
265  oh6_0->ip6.dst_address.as_u64[1] = sa0->tunnel_dst_addr.ip6.as_u64[1];
266 
267  /* in tunnel mode send it back to FIB */
268  next0 = ESP_ENCRYPT_NEXT_IP6_INPUT;
269  vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32)~0;
270  }
271  else
272  {
273  next0 = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
274  vnet_buffer (o_b0)->sw_if_index[VLIB_TX] =
275  vnet_buffer (i_b0)->sw_if_index[VLIB_TX];
276  }
277 
279 
280  if (PREDICT_TRUE(sa0->crypto_alg != IPSEC_CRYPTO_ALG_NONE)) {
281 
282  const int BLOCK_SIZE = 16;
283  const int IV_SIZE = 16;
284  int blocks = 1 + (i_b0->current_length + 1) / BLOCK_SIZE;
285 
286  /* pad packet in input buffer */
287  u8 pad_bytes = BLOCK_SIZE * blocks - 2 - i_b0->current_length;
288  u8 i;
289  u8 * padding = vlib_buffer_get_current (i_b0) + i_b0->current_length;
290  i_b0->current_length = BLOCK_SIZE * blocks;
291  for (i = 0; i < pad_bytes; ++i)
292  {
293  padding[i] = i + 1;
294  }
295  f0 = vlib_buffer_get_current (i_b0) + i_b0->current_length - 2;
296  f0->pad_length = pad_bytes;
297  f0->next_header = next_hdr_type;
298 
299  o_b0->current_length = ip_hdr_size + sizeof(esp_header_t) +
300  BLOCK_SIZE * blocks + IV_SIZE;
301 
302  vnet_buffer (o_b0)->sw_if_index[VLIB_RX] =
303  vnet_buffer (i_b0)->sw_if_index[VLIB_RX];
305 
306  u8 iv[16];
307  RAND_bytes(iv, sizeof(iv));
308 
309  clib_memcpy((u8 *) vlib_buffer_get_current (o_b0) + ip_hdr_size +
310  sizeof(esp_header_t), iv, 16 );
311 
313  (u8 *) vlib_buffer_get_current (i_b0),
314  (u8 *) vlib_buffer_get_current (o_b0) +
315  ip_hdr_size + sizeof(esp_header_t) + IV_SIZE,
316  BLOCK_SIZE * blocks,
317  sa0->crypto_key,
318  iv);
319  }
320 
321  o_b0->current_length += hmac_calc(sa0->integ_alg, sa0->integ_key,
322  sa0->integ_key_len,
323  (u8 *) o_esp0,
324  o_b0->current_length - ip_hdr_size,
325  vlib_buffer_get_current (o_b0) +
326  o_b0->current_length,
327  sa0->use_esn,
328  sa0->seq_hi);
329 
330 
331  if (PREDICT_FALSE(is_ipv6))
332  {
333  oh6_0->ip6.payload_length = clib_host_to_net_u16 (
334  vlib_buffer_length_in_chain (vm, o_b0) - sizeof(ip6_header_t));
335  }
336  else
337  {
338  oh0->ip4.length = clib_host_to_net_u16 (
339  vlib_buffer_length_in_chain (vm, o_b0));
340  oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
341  }
342 
343 trace:
345  if (o_b0) {
346  o_b0->flags |= VLIB_BUFFER_IS_TRACED;
347  o_b0->trace_index = i_b0->trace_index;
348  }
349  esp_encrypt_trace_t *tr = vlib_add_trace (vm, node, o_b0, sizeof (*tr));
350  tr->spi = sa0->spi;
351  tr->seq = sa0->seq - 1;
352  tr->crypto_alg = sa0->crypto_alg;
353  tr->integ_alg = sa0->integ_alg;
354  }
355 
356  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
357  to_next, n_left_to_next, o_bi0, next0);
358  }
359  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
360  }
362  ESP_ENCRYPT_ERROR_RX_PKTS,
363  from_frame->n_vectors);
364 
365 free_buffers_and_exit:
366  vlib_buffer_free (vm, recycle, vec_len(recycle));
367  vec_free(recycle);
368  return from_frame->n_vectors;
369 }
370 
371 
373  .function = esp_encrypt_node_fn,
374  .name = "esp-encrypt",
375  .vector_size = sizeof (u32),
376  .format_trace = format_esp_encrypt_trace,
378 
380  .error_strings = esp_encrypt_error_strings,
381 
382  .n_next_nodes = ESP_ENCRYPT_N_NEXT,
383  .next_nodes = {
384 #define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
386 #undef _
387  },
388 };
389 
#define foreach_esp_encrypt_next
Definition: esp_encrypt.c:27
void vlib_put_next_frame(vlib_main_t *vm, vlib_node_runtime_t *r, u32 next_index, u32 n_vectors_left)
Definition: main.c:459
always_inline int esp_seq_advance(ipsec_sa_t *sa)
Definition: esp_encrypt.c:114
sll srl srl sll sra u16x4 i
Definition: vector_sse2.h:267
#define CLIB_UNUSED(x)
Definition: clib.h:79
ip46_address_t tunnel_src_addr
Definition: ipsec.h:84
always_inline void esp_encrypt_aes_cbc(ipsec_crypto_alg_t alg, u8 *in, u8 *out, size_t in_len, u8 *key, u8 *iv)
Definition: esp_encrypt.c:84
vlib_node_registration_t esp_encrypt_node
(constructor) VLIB_REGISTER_NODE (esp_encrypt_node)
Definition: esp_encrypt.c:60
vlib_cli_command_t trace
(constructor) VLIB_CLI_COMMAND (trace)
Definition: memory_vlib.c:1046
bad routing header type(not 4)") sr_error (NO_MORE_SEGMENTS
#define PREDICT_TRUE(x)
Definition: clib.h:98
#define NULL
Definition: clib.h:55
esp_encrypt_next_t
Definition: esp_encrypt.c:34
static uword esp_encrypt_node_fn(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame)
Definition: esp_encrypt.c:137
ipsec_integ_alg_t integ_alg
Definition: ipsec.h:75
const EVP_CIPHER * type
Definition: esp.h:45
#define vec_add1(V, E)
Add 1 element to end of vector (unspecified alignment).
Definition: vec.h:480
ipsec_main_t ipsec_main
Definition: ipsec.h:202
u8 is_tunnel
Definition: ipsec.h:82
struct _vlib_node_registration vlib_node_registration_t
ipsec_integ_alg_t integ_alg
Definition: esp_encrypt.c:66
ipsec_crypto_alg_t crypto_alg
Definition: esp_encrypt.c:65
esp_crypto_alg_t * esp_crypto_algs
Definition: esp.h:66
always_inline void * vlib_buffer_get_current(vlib_buffer_t *b)
Get pointer to current data to process.
Definition: buffer.h:184
esp_main_t esp_main
Definition: esp.h:71
u8 crypto_key[128]
Definition: ipsec.h:73
u32 spi
Definition: ipsec.h:68
u32 seq_hi
Definition: ipsec.h:89
always_inline void ipsec_alloc_empty_buffers(vlib_main_t *vm, ipsec_main_t *im)
Definition: ipsec.h:237
i16 current_data
signed offset in data[], pre_data[] that we are currently processing.
Definition: buffer.h:77
u8 integ_key[128]
Definition: ipsec.h:77
#define vlib_prefetch_buffer_with_index(vm, bi, type)
Prefetch buffer metadata by buffer index The first 64 bytes of buffer contains most header informatio...
Definition: buffer_funcs.h:181
#define always_inline
Definition: clib.h:84
#define ESP_SEQ_MAX
Definition: esp_encrypt.c:25
u8 use_esn
Definition: ipsec.h:79
always_inline uword vlib_buffer_length_in_chain(vlib_main_t *vm, vlib_buffer_t *b)
Get length in bytes of the buffer chain.
Definition: buffer_funcs.h:112
#define clib_warning(format, args...)
Definition: error.h:59
u8 * format_ipsec_integ_alg(u8 *s, va_list *args)
Definition: ipsec_format.c:90
always_inline void * vlib_frame_vector_args(vlib_frame_t *f)
Definition: node_funcs.h:202
#define pool_elt_at_index(p, i)
Definition: pool.h:346
void vlib_buffer_free(vlib_main_t *vm, u32 *buffers, u32 n_buffers)
Free buffers Frees the entire buffer chain for each buffer.
Definition: buffer.c:1060
EVP_CIPHER_CTX encrypt_ctx
Definition: esp.h:55
u16 current_length
Nbytes between current data and the end of this buffer.
Definition: buffer.h:81
u8 is_tunnel_ip6
Definition: ipsec.h:83
uword os_get_cpu_number(void)
Definition: unix-misc.c:206
#define PREDICT_FALSE(x)
Definition: clib.h:97
always_inline void vlib_node_increment_counter(vlib_main_t *vm, u32 node_index, u32 counter_index, u64 increment)
Definition: node_funcs.h:970
#define vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next, n_left_to_next, bi0, next0)
Definition: buffer_node.h:83
#define vlib_get_next_frame(vm, node, next_index, vectors, n_vectors_left)
Definition: node_funcs.h:265
always_inline u16 ip4_header_checksum(ip4_header_t *i)
Definition: ip4_packet.h:194
ip46_address_t tunnel_dst_addr
Definition: ipsec.h:85
u16 n_vectors
Definition: node.h:307
#define vec_free(V)
Free vector&#39;s memory (no header).
Definition: vec.h:298
static u8 * format_esp_encrypt_trace(u8 *s, va_list *args)
Definition: esp_encrypt.c:70
#define clib_memcpy(a, b, c)
Definition: string.h:63
#define VLIB_BUFFER_TOTAL_LENGTH_VALID
Definition: buffer.h:95
#define ARRAY_LEN(x)
Definition: clib.h:59
esp_encrypt_error_t
Definition: esp_encrypt.c:47
u16 cached_next_index
Definition: node.h:422
#define ASSERT(truth)
unsigned int u32
Definition: types.h:88
#define vnet_buffer(b)
Definition: buffer.h:300
static char * esp_encrypt_error_strings[]
Definition: esp_encrypt.c:54
ipsec_sa_t * sad
Definition: ipsec.h:172
u8 * format(u8 *s, char *fmt,...)
Definition: format.c:405
ipsec_crypto_alg_t
Definition: ipsec.h:38
u8 integ_key_len
Definition: ipsec.h:76
#define VLIB_BUFFER_IS_TRACED
Definition: buffer.h:91
u32 seq
Definition: ipsec.h:88
u64 uword
Definition: types.h:112
#define foreach_esp_encrypt_error
Definition: esp_encrypt.c:40
Definition: defs.h:46
ipsec_crypto_alg_t last_encrypt_alg
Definition: esp.h:60
#define vec_len(v)
Number of elements in vector (rvalue-only, NULL tolerant)
unsigned char u8
Definition: types.h:56
always_inline void * vlib_add_trace(vlib_main_t *vm, vlib_node_runtime_t *r, vlib_buffer_t *b, u32 n_data_bytes)
Definition: trace_funcs.h:55
ipsec_crypto_alg_t crypto_alg
Definition: ipsec.h:71
#define VLIB_REGISTER_NODE(x,...)
Definition: node.h:140
always_inline unsigned int hmac_calc(ipsec_integ_alg_t alg, u8 *key, int key_len, u8 *data, int data_len, u8 *signature, u8 use_esn, u32 seq_hi)
Definition: esp.h:121
Definition: esp.h:65
u32 flags
buffer flags: VLIB_BUFFER_IS_TRACED: trace this buffer.
Definition: buffer.h:84
u32 ** empty_buffers
Definition: ipsec.h:178
u8 * format_ipsec_crypto_alg(u8 *s, va_list *args)
Definition: ipsec_format.c:58
u8 use_anti_replay
Definition: ipsec.h:80
always_inline vlib_buffer_t * vlib_get_buffer(vlib_main_t *vm, u32 buffer_index)
Translate buffer index into buffer pointer.
Definition: buffer_funcs.h:69
esp_main_per_thread_data_t * per_thread_data
Definition: esp.h:68
u32 trace_index
Specifies index into trace buffer if VLIB_PACKET_IS_TRACED flag is set.
Definition: buffer.h:116
Definition: defs.h:45
ipsec_integ_alg_t
Definition: ipsec.h:54