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Vector Packet Processing
ah_encrypt.c
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1 /*
2  * ah_encrypt.c : IPSec AH 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 #include <vnet/ipsec/ah.h>
25 
26 #define foreach_ah_encrypt_next \
27 _(DROP, "error-drop") \
28 _(IP4_LOOKUP, "ip4-lookup") \
29 _(IP6_LOOKUP, "ip6-lookup") \
30 _(INTERFACE_OUTPUT, "interface-output")
31 
32 #define _(v, s) AH_ENCRYPT_NEXT_##v,
33 typedef enum
34 {
36 #undef _
39 
40 #define foreach_ah_encrypt_error \
41  _(RX_PKTS, "AH pkts received") \
42  _(SEQ_CYCLED, "sequence number cycled")
43 
44 
45 typedef enum
46 {
47 #define _(sym,str) AH_ENCRYPT_ERROR_##sym,
49 #undef _
52 
53 static char *ah_encrypt_error_strings[] = {
54 #define _(sym,string) string,
56 #undef _
57 };
58 
60 
61 typedef struct
62 {
67 
68 /* packet trace format function */
69 static u8 *
70 format_ah_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  ah_encrypt_trace_t *t = va_arg (*args, ah_encrypt_trace_t *);
75 
76  s = format (s, "ah: spi %u seq %u integrity %U",
78  return s;
79 }
80 
81 static uword
83  vlib_node_runtime_t * node, vlib_frame_t * from_frame)
84 {
85  u32 n_left_from, *from, *to_next = 0, next_index;
86  int icv_size = 0;
87  from = vlib_frame_vector_args (from_frame);
88  n_left_from = from_frame->n_vectors;
89  ipsec_main_t *im = &ipsec_main;
91  next_index = node->cached_next_index;
92 
93  while (n_left_from > 0)
94  {
95  u32 n_left_to_next;
96 
97  vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
98 
99  while (n_left_from > 0 && n_left_to_next > 0)
100  {
101  u32 i_bi0, next0;
102  vlib_buffer_t *i_b0 = 0;
103  u32 sa_index0;
104  ipsec_sa_t *sa0;
105  ip4_and_ah_header_t *ih0, *oh0 = 0;
106  ip6_and_ah_header_t *ih6_0, *oh6_0 = 0;
107  u8 is_ipv6;
108  u8 ip_hdr_size;
109  u8 next_hdr_type;
110  u8 transport_mode = 0;
111  u8 tos = 0;
112  u8 ttl = 0;
113  u8 hop_limit = 0;
114  u32 ip_version_traffic_class_and_flow_label = 0;
115 
116  i_bi0 = from[0];
117  from += 1;
118  n_left_from -= 1;
119  n_left_to_next -= 1;
120  next0 = AH_ENCRYPT_NEXT_DROP;
121 
122  i_b0 = vlib_get_buffer (vm, i_bi0);
123  to_next[0] = i_bi0;
124  to_next += 1;
125  sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
126  sa0 = pool_elt_at_index (im->sad, sa_index0);
127 
128  if (PREDICT_FALSE (esp_seq_advance (sa0)))
129  {
130  clib_warning ("sequence number counter has cycled SPI %u",
131  sa0->spi);
133  AH_ENCRYPT_ERROR_SEQ_CYCLED, 1);
134  //TODO need to confirm if below is needed
135  to_next[0] = i_bi0;
136  to_next += 1;
137  goto trace;
138  }
139 
140 
141  sa0->total_data_size += i_b0->current_length;
142 
143  ssize_t adv;
144  ih0 = vlib_buffer_get_current (i_b0);
145  ttl = ih0->ip4.ttl;
146  tos = ih0->ip4.tos;
147 
148  is_ipv6 = (ih0->ip4.ip_version_and_header_length & 0xF0) == 0x60;
149  /* is ipv6 */
150  if (PREDICT_TRUE (sa0->is_tunnel))
151  {
152  if (PREDICT_TRUE (!is_ipv6))
153  adv = -sizeof (ip4_and_ah_header_t);
154  else
155  adv = -sizeof (ip6_and_ah_header_t);
156  }
157  else
158  {
159  adv = -sizeof (ah_header_t);
160  }
161 
162  icv_size =
164  const u8 padding_len = ah_calc_icv_padding_len (icv_size, is_ipv6);
165  adv -= padding_len;
166  /*transport mode save the eth header before it is overwritten */
167  if (PREDICT_FALSE (!sa0->is_tunnel))
168  {
170  ((u8 *) vlib_buffer_get_current (i_b0) -
171  sizeof (ethernet_header_t));
172  ethernet_header_t *oeh0 =
173  (ethernet_header_t *) ((u8 *) ieh0 + (adv - icv_size));
174  clib_memcpy (oeh0, ieh0, sizeof (ethernet_header_t));
175  }
176 
177  vlib_buffer_advance (i_b0, adv - icv_size);
178 
179  if (PREDICT_FALSE (is_ipv6))
180  { /* is ipv6 */
181  ih6_0 = (ip6_and_ah_header_t *) ih0;
182  ip_hdr_size = sizeof (ip6_header_t);
183  oh6_0 = vlib_buffer_get_current (i_b0);
184 
185  hop_limit = ih6_0->ip6.hop_limit;
186  ip_version_traffic_class_and_flow_label =
187  ih6_0->ip6.ip_version_traffic_class_and_flow_label;
188  if (PREDICT_TRUE (sa0->is_tunnel))
189  {
190  next_hdr_type = IP_PROTOCOL_IPV6;
191  }
192  else
193  {
194  next_hdr_type = ih6_0->ip6.protocol;
195  memmove (oh6_0, ih6_0, sizeof (ip6_header_t));
196  }
197 
198  oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_AH;
199  oh6_0->ip6.hop_limit = 0;
200  oh6_0->ip6.ip_version_traffic_class_and_flow_label = 0x60;
201  oh6_0->ah.reserved = 0;
202  oh6_0->ah.nexthdr = next_hdr_type;
203  oh6_0->ah.spi = clib_net_to_host_u32 (sa0->spi);
204  oh6_0->ah.seq_no = clib_net_to_host_u32 (sa0->seq);
205  oh6_0->ip6.payload_length =
206  clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, i_b0) -
207  sizeof (ip6_header_t));
208  oh6_0->ah.hdrlen =
209  (sizeof (ah_header_t) + icv_size + padding_len) / 4 - 2;
210  }
211  else
212  {
213  ip_hdr_size = sizeof (ip4_header_t);
214  oh0 = vlib_buffer_get_current (i_b0);
215  memset (oh0, 0, sizeof (ip4_and_ah_header_t));
216 
217  if (PREDICT_TRUE (sa0->is_tunnel))
218  {
219  next_hdr_type = IP_PROTOCOL_IP_IN_IP;
220  }
221  else
222  {
223  next_hdr_type = ih0->ip4.protocol;
224  memmove (oh0, ih0, sizeof (ip4_header_t));
225  }
226 
227  oh0->ip4.length =
228  clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, i_b0));
229  oh0->ip4.ip_version_and_header_length = 0x45;
230  oh0->ip4.fragment_id = 0;
231  oh0->ip4.flags_and_fragment_offset = 0;
232  oh0->ip4.ttl = 0;
233  oh0->ip4.tos = 0;
234  oh0->ip4.protocol = IP_PROTOCOL_IPSEC_AH;
235  oh0->ah.spi = clib_net_to_host_u32 (sa0->spi);
236  oh0->ah.seq_no = clib_net_to_host_u32 (sa0->seq);
237  oh0->ip4.checksum = 0;
238  oh0->ah.nexthdr = next_hdr_type;
239  oh0->ah.hdrlen =
240  (sizeof (ah_header_t) + icv_size + padding_len) / 4 - 2;
241  }
242 
243 
244  if (PREDICT_TRUE
245  (!is_ipv6 && sa0->is_tunnel && !sa0->is_tunnel_ip6))
246  {
247  oh0->ip4.src_address.as_u32 = sa0->tunnel_src_addr.ip4.as_u32;
248  oh0->ip4.dst_address.as_u32 = sa0->tunnel_dst_addr.ip4.as_u32;
249 
250  next0 = AH_ENCRYPT_NEXT_IP4_LOOKUP;
251  vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
252  }
253  else if (is_ipv6 && sa0->is_tunnel && sa0->is_tunnel_ip6)
254  {
255  oh6_0->ip6.src_address.as_u64[0] =
256  sa0->tunnel_src_addr.ip6.as_u64[0];
257  oh6_0->ip6.src_address.as_u64[1] =
258  sa0->tunnel_src_addr.ip6.as_u64[1];
259  oh6_0->ip6.dst_address.as_u64[0] =
260  sa0->tunnel_dst_addr.ip6.as_u64[0];
261  oh6_0->ip6.dst_address.as_u64[1] =
262  sa0->tunnel_dst_addr.ip6.as_u64[1];
263 
264  next0 = AH_ENCRYPT_NEXT_IP6_LOOKUP;
265  vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
266  }
267  else
268  {
269  transport_mode = 1;
270  next0 = AH_ENCRYPT_NEXT_INTERFACE_OUTPUT;
271  }
272 
273  u8 sig[64];
274  memset (sig, 0, sizeof (sig));
275  u8 *digest =
276  vlib_buffer_get_current (i_b0) + ip_hdr_size +
277  sizeof (ah_header_t);
278  memset (digest, 0, icv_size);
279 
280  unsigned size = hmac_calc (sa0->integ_alg, sa0->integ_key,
281  sa0->integ_key_len,
283  i_b0->current_length, sig, sa0->use_esn,
284  sa0->seq_hi);
285 
286  memcpy (digest, sig, size);
287  if (PREDICT_FALSE (is_ipv6))
288  {
289  oh6_0->ip6.hop_limit = hop_limit;
290  oh6_0->ip6.ip_version_traffic_class_and_flow_label =
291  ip_version_traffic_class_and_flow_label;
292  }
293  else
294  {
295  oh0->ip4.ttl = ttl;
296  oh0->ip4.tos = tos;
297  oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
298  }
299 
300  if (transport_mode)
301  vlib_buffer_advance (i_b0, -sizeof (ethernet_header_t));
302 
303  trace:
304  if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
305  {
306  i_b0->flags |= VLIB_BUFFER_IS_TRACED;
307  ah_encrypt_trace_t *tr =
308  vlib_add_trace (vm, node, i_b0, sizeof (*tr));
309  tr->spi = sa0->spi;
310  tr->seq = sa0->seq - 1;
311  tr->integ_alg = sa0->integ_alg;
312  }
313 
314  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
315  to_next, n_left_to_next, i_bi0,
316  next0);
317  }
318  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
319  }
321  AH_ENCRYPT_ERROR_RX_PKTS,
322  from_frame->n_vectors);
323 
324  return from_frame->n_vectors;
325 }
326 
327 
328 /* *INDENT-OFF* */
330  .function = ah_encrypt_node_fn,
331  .name = "ah-encrypt",
332  .vector_size = sizeof (u32),
333  .format_trace = format_ah_encrypt_trace,
334  .type = VLIB_NODE_TYPE_INTERNAL,
335 
336  .n_errors = ARRAY_LEN(ah_encrypt_error_strings),
337  .error_strings = ah_encrypt_error_strings,
338 
339  .n_next_nodes = AH_ENCRYPT_N_NEXT,
340  .next_nodes = {
341 #define _(s,n) [AH_ENCRYPT_NEXT_##s] = n,
343 #undef _
344  },
345 };
346 /* *INDENT-ON* */
347 
349 /*
350  * fd.io coding-style-patch-verification: ON
351  *
352  * Local Variables:
353  * eval: (c-set-style "gnu")
354  * End:
355  */
static vlib_cli_command_t trace
(constructor) VLIB_CLI_COMMAND (trace)
Definition: vlib_api_cli.c:862
#define CLIB_UNUSED(x)
Definition: clib.h:81
ip46_address_t tunnel_src_addr
Definition: ipsec.h:131
ipsec_proto_main_integ_alg_t * ipsec_proto_main_integ_algs
Definition: esp.h:101
#define PREDICT_TRUE(x)
Definition: clib.h:108
static 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:331
ipsec_integ_alg_t integ_alg
Definition: ipsec.h:121
u8 is_tunnel
Definition: ipsec.h:128
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:419
static 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:263
unsigned char u8
Definition: types.h:56
u32 spi
Definition: ipsec.h:114
u32 seq_hi
Definition: ipsec.h:138
static int esp_seq_advance(ipsec_sa_t *sa)
Definition: esp.h:233
memset(h->entries, 0, sizeof(h->entries[0])*entries)
u8 integ_key[128]
Definition: ipsec.h:123
ipsec_main_t ipsec_main
Definition: ipsec.c:30
u8 use_esn
Definition: ipsec.h:125
unsigned int u32
Definition: types.h:88
ipsec_integ_alg_t integ_alg
Definition: ah_encrypt.c:65
static u8 ah_calc_icv_padding_len(u8 icv_size, int is_ipv6)
Definition: ah.h:53
#define VLIB_NODE_FUNCTION_MULTIARCH(node, fn)
Definition: node.h:209
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:464
uword size
ipsec_integ_alg_t
Definition: ipsec.h:97
u16 current_length
Nbytes between current data and the end of this buffer.
Definition: buffer.h:113
u8 is_tunnel_ip6
Definition: ipsec.h:129
static void * vlib_buffer_get_current(vlib_buffer_t *b)
Get pointer to current data to process.
Definition: buffer.h:205
#define PREDICT_FALSE(x)
Definition: clib.h:107
ah_encrypt_next_t
Definition: ah_encrypt.c:33
#define vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next, n_left_to_next, bi0, next0)
Finish enqueueing one buffer forward in the graph.
Definition: buffer_node.h:218
#define vlib_get_next_frame(vm, node, next_index, vectors, n_vectors_left)
Get pointer to next frame vector data by (vlib_node_runtime_t, next_index).
Definition: node_funcs.h:364
static void vlib_node_increment_counter(vlib_main_t *vm, u32 node_index, u32 counter_index, u64 increment)
Definition: node_funcs.h:1176
ip46_address_t tunnel_dst_addr
Definition: ipsec.h:132
static u8 * format_ah_encrypt_trace(u8 *s, va_list *args)
Definition: ah_encrypt.c:70
#define VLIB_REGISTER_NODE(x,...)
Definition: node.h:155
u16 n_vectors
Definition: node.h:401
vlib_main_t * vm
Definition: buffer.c:294
static char * ah_encrypt_error_strings[]
Definition: ah_encrypt.c:53
#define clib_warning(format, args...)
Definition: error.h:59
#define clib_memcpy(a, b, c)
Definition: string.h:75
#define ARRAY_LEN(x)
Definition: clib.h:61
void vlib_put_next_frame(vlib_main_t *vm, vlib_node_runtime_t *r, u32 next_index, u32 n_vectors_left)
Release pointer to next frame vector data.
Definition: main.c:455
u16 cached_next_index
Next frame index that vector arguments were last enqueued to last time this node ran.
Definition: node.h:513
#define foreach_ah_encrypt_error
Definition: ah_encrypt.c:40
ipsec_sa_t * sad
Definition: ipsec.h:265
u64 total_data_size
Definition: ipsec.h:144
u8 integ_key_len
Definition: ipsec.h:122
static void vlib_buffer_advance(vlib_buffer_t *b, word l)
Advance current data pointer by the supplied (signed!) amount.
Definition: buffer.h:218
u32 seq
Definition: ipsec.h:137
static 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:57
u8 * format_ipsec_integ_alg(u8 *s, va_list *args)
Definition: ipsec_format.c:90
struct _vlib_node_registration vlib_node_registration_t
Definition: defs.h:47
static uword ah_encrypt_node_fn(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame)
Definition: ah_encrypt.c:82
u64 uword
Definition: types.h:112
static void * vlib_frame_vector_args(vlib_frame_t *f)
Get pointer to frame vector data.
Definition: node_funcs.h:267
#define vnet_buffer(b)
Definition: buffer.h:344
Definition: ah.h:27
ipsec_proto_main_t ipsec_proto_main
Definition: esp_encrypt.c:26
ah_encrypt_error_t
Definition: ah_encrypt.c:45
#define foreach_ah_encrypt_next
Definition: ah_encrypt.c:26
vlib_node_registration_t ah_encrypt_node
(constructor) VLIB_REGISTER_NODE (ah_encrypt_node)
Definition: ah_encrypt.c:59
u32 flags
buffer flags: VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index, VLIB_BUFFER_IS_TRACED: trace this buffer.
Definition: buffer.h:116
static vlib_buffer_t * vlib_get_buffer(vlib_main_t *vm, u32 buffer_index)
Translate buffer index into buffer pointer.
Definition: buffer_funcs.h:58
static u16 ip4_header_checksum(ip4_header_t *i)
Definition: ip4_packet.h:246