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“mukeshyadav1984”430ac932017-11-23 02:39:33 -08001/*
2 * ah_decrypt.c : IPSec AH decrypt 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
Klement Sekerabe5a5dd2018-10-09 16:05:48 +020026#define foreach_ah_decrypt_next \
27 _ (DROP, "error-drop") \
28 _ (IP4_INPUT, "ip4-input") \
29 _ (IP6_INPUT, "ip6-input") \
30 _ (IPSEC_GRE_INPUT, "ipsec-gre-input")
“mukeshyadav1984”430ac932017-11-23 02:39:33 -080031
32#define _(v, s) AH_DECRYPT_NEXT_##v,
33typedef enum
34{
35 foreach_ah_decrypt_next
36#undef _
37 AH_DECRYPT_N_NEXT,
38} ah_decrypt_next_t;
39
Klement Sekerabe5a5dd2018-10-09 16:05:48 +020040#define foreach_ah_decrypt_error \
41 _ (RX_PKTS, "AH pkts received") \
42 _ (DECRYPTION_FAILED, "AH decryption failed") \
43 _ (INTEG_ERROR, "Integrity check failed") \
44 _ (REPLAY, "SA replayed packet")
“mukeshyadav1984”430ac932017-11-23 02:39:33 -080045
46typedef enum
47{
48#define _(sym,str) AH_DECRYPT_ERROR_##sym,
49 foreach_ah_decrypt_error
50#undef _
51 AH_DECRYPT_N_ERROR,
52} ah_decrypt_error_t;
53
54static char *ah_decrypt_error_strings[] = {
55#define _(sym,string) string,
56 foreach_ah_decrypt_error
57#undef _
58};
59
60typedef struct
61{
62 ipsec_integ_alg_t integ_alg;
63} ah_decrypt_trace_t;
64
65/* packet trace format function */
66static u8 *
67format_ah_decrypt_trace (u8 * s, va_list * args)
68{
69 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
70 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
71 ah_decrypt_trace_t *t = va_arg (*args, ah_decrypt_trace_t *);
72
73 s = format (s, "ah: integrity %U", format_ipsec_integ_alg, t->integ_alg);
74 return s;
75}
76
Klement Sekerabe5a5dd2018-10-09 16:05:48 +020077always_inline uword
78ah_decrypt_inline (vlib_main_t * vm,
79 vlib_node_runtime_t * node, vlib_frame_t * from_frame,
80 int is_ip6)
“mukeshyadav1984”430ac932017-11-23 02:39:33 -080081{
82 u32 n_left_from, *from, next_index, *to_next;
83 ipsec_main_t *im = &ipsec_main;
84 ipsec_proto_main_t *em = &ipsec_proto_main;
85 from = vlib_frame_vector_args (from_frame);
86 n_left_from = from_frame->n_vectors;
87 int icv_size = 0;
88
89 next_index = node->cached_next_index;
90
91 while (n_left_from > 0)
92 {
93 u32 n_left_to_next;
94
95 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
96
97 while (n_left_from > 0 && n_left_to_next > 0)
98 {
99 u32 i_bi0;
100 u32 next0;
101 vlib_buffer_t *i_b0;
102 ah_header_t *ah0;
103 ipsec_sa_t *sa0;
104 u32 sa_index0 = ~0;
105 u32 seq;
106 ip4_header_t *ih4 = 0, *oh4 = 0;
107 ip6_header_t *ih6 = 0, *oh6 = 0;
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800108 u8 ip_hdr_size = 0;
109 u8 tos = 0;
110 u8 ttl = 0;
Klement Sekera611864f2018-09-26 11:19:00 +0200111 u32 ip_version_traffic_class_and_flow_label = 0;
112 u8 hop_limit = 0;
113 u8 nexthdr = 0;
114 u8 icv_padding_len = 0;
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800115
116
117 i_bi0 = from[0];
118 from += 1;
119 n_left_from -= 1;
120 n_left_to_next -= 1;
121
122 next0 = AH_DECRYPT_NEXT_DROP;
123
124 i_b0 = vlib_get_buffer (vm, i_bi0);
125 to_next[0] = i_bi0;
126 to_next += 1;
127 ih4 = vlib_buffer_get_current (i_b0);
Klement Sekera611864f2018-09-26 11:19:00 +0200128 ih6 = vlib_buffer_get_current (i_b0);
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800129 sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
130 sa0 = pool_elt_at_index (im->sad, sa_index0);
131
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200132 if (is_ip6)
Klement Sekera611864f2018-09-26 11:19:00 +0200133 {
134 ip6_ext_header_t *prev = NULL;
135 ip6_ext_header_find_t (ih6, prev, ah0, IP_PROTOCOL_IPSEC_AH);
136 ip_hdr_size = sizeof (ip6_header_t);
137 ASSERT ((u8 *) ah0 - (u8 *) ih6 == ip_hdr_size);
138 }
139 else
140 {
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200141 ip_hdr_size = ip4_header_bytes (ih4);
142 ah0 = (ah_header_t *) ((u8 *) ih4 + ip_hdr_size);
Klement Sekera611864f2018-09-26 11:19:00 +0200143 }
144
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800145 seq = clib_host_to_net_u32 (ah0->seq_no);
146 /* anti-replay check */
147 //TODO UT remaining
148 if (sa0->use_anti_replay)
149 {
150 int rv = 0;
151
152 if (PREDICT_TRUE (sa0->use_esn))
153 rv = esp_replay_check_esn (sa0, seq);
154 else
155 rv = esp_replay_check (sa0, seq);
156
157 if (PREDICT_FALSE (rv))
158 {
159 clib_warning ("anti-replay SPI %u seq %u", sa0->spi, seq);
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200160 if (is_ip6)
161 vlib_node_increment_counter (vm,
162 ah6_decrypt_node.index,
163 AH_DECRYPT_ERROR_REPLAY, 1);
164 else
165 vlib_node_increment_counter (vm,
166 ah6_decrypt_node.index,
167 AH_DECRYPT_ERROR_REPLAY, 1);
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800168 to_next[0] = i_bi0;
169 to_next += 1;
170 goto trace;
171 }
172 }
173
174
175 sa0->total_data_size += i_b0->current_length;
176 icv_size =
177 em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
178 if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
179 {
180 u8 sig[64];
181 u8 digest[64];
182 memset (sig, 0, sizeof (sig));
183 memset (digest, 0, sizeof (digest));
Klement Sekera611864f2018-09-26 11:19:00 +0200184 u8 *icv = ah0->auth_data;
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800185 memcpy (digest, icv, icv_size);
186 memset (icv, 0, icv_size);
187
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200188 if (is_ip6)
Klement Sekera611864f2018-09-26 11:19:00 +0200189 {
190 ip_version_traffic_class_and_flow_label =
191 ih6->ip_version_traffic_class_and_flow_label;
192 hop_limit = ih6->hop_limit;
193 ih6->ip_version_traffic_class_and_flow_label = 0x60;
194 ih6->hop_limit = 0;
195 nexthdr = ah0->nexthdr;
196 icv_padding_len =
197 ah_calc_icv_padding_len (icv_size, 1 /* is_ipv6 */ );
198 }
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200199 else
200 {
201 tos = ih4->tos;
202 ttl = ih4->ttl;
203 ih4->tos = 0;
204 ih4->ttl = 0;
205 ih4->checksum = 0;
206 ih4->flags_and_fragment_offset = 0;
207 icv_padding_len =
208 ah_calc_icv_padding_len (icv_size, 0 /* is_ipv6 */ );
209 }
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800210 hmac_calc (sa0->integ_alg, sa0->integ_key, sa0->integ_key_len,
211 (u8 *) ih4, i_b0->current_length, sig, sa0->use_esn,
212 sa0->seq_hi);
213
214 if (PREDICT_FALSE (memcmp (digest, sig, icv_size)))
215 {
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200216 if (is_ip6)
217 vlib_node_increment_counter (vm,
218 ah6_decrypt_node.index,
219 AH_DECRYPT_ERROR_INTEG_ERROR,
220 1);
221 else
222 vlib_node_increment_counter (vm,
223 ah4_decrypt_node.index,
224 AH_DECRYPT_ERROR_INTEG_ERROR,
225 1);
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800226 to_next[0] = i_bi0;
227 to_next += 1;
228 goto trace;
229 }
230
231 //TODO UT remaining
232 if (PREDICT_TRUE (sa0->use_anti_replay))
233 {
234 if (PREDICT_TRUE (sa0->use_esn))
235 esp_replay_advance_esn (sa0, seq);
236 else
237 esp_replay_advance (sa0, seq);
238 }
239
240 }
241
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800242 vlib_buffer_advance (i_b0,
Klement Sekera611864f2018-09-26 11:19:00 +0200243 ip_hdr_size + sizeof (ah_header_t) + icv_size +
244 icv_padding_len);
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800245 i_b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
246
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200247 if (PREDICT_TRUE (sa0->is_tunnel))
248 { /* tunnel mode */
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800249 if (PREDICT_TRUE (ah0->nexthdr == IP_PROTOCOL_IP_IN_IP))
250 next0 = AH_DECRYPT_NEXT_IP4_INPUT;
251 else if (ah0->nexthdr == IP_PROTOCOL_IPV6)
252 next0 = AH_DECRYPT_NEXT_IP6_INPUT;
253 else
254 {
255 clib_warning ("next header: 0x%x", ah0->nexthdr);
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200256 if (is_ip6)
257 vlib_node_increment_counter (vm,
258 ah6_decrypt_node.index,
259 AH_DECRYPT_ERROR_DECRYPTION_FAILED,
260 1);
261 else
262 vlib_node_increment_counter (vm,
263 ah4_decrypt_node.index,
264 AH_DECRYPT_ERROR_DECRYPTION_FAILED,
265 1);
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800266 goto trace;
267 }
268 }
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800269 else
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200270 { /* transport mode */
271 if (is_ip6)
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800272 {
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800273 vlib_buffer_advance (i_b0, -sizeof (ip6_header_t));
274 oh6 = vlib_buffer_get_current (i_b0);
275 memmove (oh6, ih6, sizeof (ip6_header_t));
276
277 next0 = AH_DECRYPT_NEXT_IP6_INPUT;
Klement Sekera611864f2018-09-26 11:19:00 +0200278 oh6->protocol = nexthdr;
279 oh6->hop_limit = hop_limit;
280 oh6->ip_version_traffic_class_and_flow_label =
281 ip_version_traffic_class_and_flow_label;
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800282 oh6->payload_length =
283 clib_host_to_net_u16 (vlib_buffer_length_in_chain
284 (vm, i_b0) - sizeof (ip6_header_t));
285 }
286 else
287 {
288 vlib_buffer_advance (i_b0, -sizeof (ip4_header_t));
289 oh4 = vlib_buffer_get_current (i_b0);
290 memmove (oh4, ih4, sizeof (ip4_header_t));
291
292 next0 = AH_DECRYPT_NEXT_IP4_INPUT;
293 oh4->ip_version_and_header_length = 0x45;
294 oh4->fragment_id = 0;
295 oh4->flags_and_fragment_offset = 0;
296 oh4->protocol = ah0->nexthdr;
297 oh4->length =
298 clib_host_to_net_u16 (vlib_buffer_length_in_chain
299 (vm, i_b0));
300 oh4->ttl = ttl;
301 oh4->tos = tos;
302 oh4->checksum = ip4_header_checksum (oh4);
303 }
304 }
305
306 /* for IPSec-GRE tunnel next node is ipsec-gre-input */
307 if (PREDICT_FALSE
308 ((vnet_buffer (i_b0)->ipsec.flags) &
309 IPSEC_FLAG_IPSEC_GRE_TUNNEL))
310 next0 = AH_DECRYPT_NEXT_IPSEC_GRE_INPUT;
311
312
313 vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
314 trace:
315 if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
316 {
317 i_b0->flags |= VLIB_BUFFER_IS_TRACED;
318 ah_decrypt_trace_t *tr =
319 vlib_add_trace (vm, node, i_b0, sizeof (*tr));
320 tr->integ_alg = sa0->integ_alg;
321 }
322 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
323 n_left_to_next, i_bi0, next0);
324 }
325 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
326 }
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200327 if (is_ip6)
328 vlib_node_increment_counter (vm, ah6_decrypt_node.index,
329 AH_DECRYPT_ERROR_RX_PKTS,
330 from_frame->n_vectors);
331 else
332 vlib_node_increment_counter (vm, ah4_decrypt_node.index,
333 AH_DECRYPT_ERROR_RX_PKTS,
334 from_frame->n_vectors);
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800335
336 return from_frame->n_vectors;
337}
338
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200339static uword
340ah4_decrypt_node_fn (vlib_main_t * vm,
341 vlib_node_runtime_t * node, vlib_frame_t * from_frame)
342{
343 return ah_decrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
344}
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800345
346/* *INDENT-OFF* */
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200347VLIB_REGISTER_NODE (ah4_decrypt_node) = {
348 .function = ah4_decrypt_node_fn,
349 .name = "ah4-decrypt",
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800350 .vector_size = sizeof (u32),
351 .format_trace = format_ah_decrypt_trace,
352 .type = VLIB_NODE_TYPE_INTERNAL,
353
354 .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
355 .error_strings = ah_decrypt_error_strings,
356
357 .n_next_nodes = AH_DECRYPT_N_NEXT,
358 .next_nodes = {
359#define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
360 foreach_ah_decrypt_next
361#undef _
362 },
363};
364/* *INDENT-ON* */
365
Klement Sekerabe5a5dd2018-10-09 16:05:48 +0200366VLIB_NODE_FUNCTION_MULTIARCH (ah4_decrypt_node, ah4_decrypt_node_fn);
367
368static uword
369ah6_decrypt_node_fn (vlib_main_t * vm,
370 vlib_node_runtime_t * node, vlib_frame_t * from_frame)
371{
372 return ah_decrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
373}
374
375/* *INDENT-OFF* */
376VLIB_REGISTER_NODE (ah6_decrypt_node) = {
377 .function = ah6_decrypt_node_fn,
378 .name = "ah6-decrypt",
379 .vector_size = sizeof (u32),
380 .format_trace = format_ah_decrypt_trace,
381 .type = VLIB_NODE_TYPE_INTERNAL,
382
383 .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
384 .error_strings = ah_decrypt_error_strings,
385
386 .n_next_nodes = AH_DECRYPT_N_NEXT,
387 .next_nodes = {
388#define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
389 foreach_ah_decrypt_next
390#undef _
391 },
392};
393/* *INDENT-ON* */
394
395VLIB_NODE_FUNCTION_MULTIARCH (ah6_decrypt_node, ah6_decrypt_node_fn);
“mukeshyadav1984”430ac932017-11-23 02:39:33 -0800396/*
397 * fd.io coding-style-patch-verification: ON
398 *
399 * Local Variables:
400 * eval: (c-set-style "gnu")
401 * End:
402 */