2 * ah_decrypt.c : IPSec AH decrypt node
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:
9 * http://www.apache.org/licenses/LICENSE-2.0
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.
18 #include <vnet/vnet.h>
19 #include <vnet/api_errno.h>
20 #include <vnet/ip/ip.h>
22 #include <vnet/ipsec/ipsec.h>
23 #include <vnet/ipsec/esp.h>
24 #include <vnet/ipsec/ah.h>
25 #include <vnet/ipsec/ipsec_io.h>
27 #define foreach_ah_decrypt_next \
28 _ (DROP, "error-drop") \
29 _ (IP4_INPUT, "ip4-input") \
30 _ (IP6_INPUT, "ip6-input") \
31 _ (IPSEC_GRE_INPUT, "ipsec-gre-input")
33 #define _(v, s) AH_DECRYPT_NEXT_##v,
36 foreach_ah_decrypt_next
41 #define foreach_ah_decrypt_error \
42 _ (RX_PKTS, "AH pkts received") \
43 _ (DECRYPTION_FAILED, "AH decryption failed") \
44 _ (INTEG_ERROR, "Integrity check failed") \
45 _ (REPLAY, "SA replayed packet")
49 #define _(sym,str) AH_DECRYPT_ERROR_##sym,
50 foreach_ah_decrypt_error
55 static char *ah_decrypt_error_strings[] = {
56 #define _(sym,string) string,
57 foreach_ah_decrypt_error
63 ipsec_integ_alg_t integ_alg;
67 /* packet trace format function */
69 format_ah_decrypt_trace (u8 * s, va_list * args)
71 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
72 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
73 ah_decrypt_trace_t *t = va_arg (*args, ah_decrypt_trace_t *);
75 s = format (s, "ah: integrity %U seq-num %d",
76 format_ipsec_integ_alg, t->integ_alg, t->seq_num);
81 ah_decrypt_inline (vlib_main_t * vm,
82 vlib_node_runtime_t * node, vlib_frame_t * from_frame,
85 u32 n_left_from, *from, next_index, *to_next, thread_index;
86 ipsec_main_t *im = &ipsec_main;
87 from = vlib_frame_vector_args (from_frame);
88 n_left_from = from_frame->n_vectors;
91 next_index = node->cached_next_index;
92 thread_index = vm->thread_index;
94 while (n_left_from > 0)
98 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
100 while (n_left_from > 0 && n_left_to_next > 0)
109 ip4_header_t *ih4 = 0, *oh4 = 0;
110 ip6_header_t *ih6 = 0, *oh6 = 0;
114 u32 ip_version_traffic_class_and_flow_label = 0;
117 u8 icv_padding_len = 0;
125 next0 = AH_DECRYPT_NEXT_DROP;
127 i_b0 = vlib_get_buffer (vm, i_bi0);
130 ih4 = vlib_buffer_get_current (i_b0);
131 ih6 = vlib_buffer_get_current (i_b0);
132 sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
133 sa0 = pool_elt_at_index (im->sad, sa_index0);
135 vlib_prefetch_combined_counter (&ipsec_sa_counters,
136 thread_index, sa_index0);
140 ip6_ext_header_t *prev = NULL;
141 ip6_ext_header_find_t (ih6, prev, ah0, IP_PROTOCOL_IPSEC_AH);
142 ip_hdr_size = sizeof (ip6_header_t);
143 ASSERT ((u8 *) ah0 - (u8 *) ih6 == ip_hdr_size);
147 ip_hdr_size = ip4_header_bytes (ih4);
148 ah0 = (ah_header_t *) ((u8 *) ih4 + ip_hdr_size);
151 seq = clib_host_to_net_u32 (ah0->seq_no);
153 /* anti-replay check */
154 if (ipsec_sa_anti_replay_check (sa0, &ah0->seq_no))
156 i_b0->error = node->errors[AH_DECRYPT_ERROR_REPLAY];
160 vlib_increment_combined_counter
161 (&ipsec_sa_counters, thread_index, sa_index0,
162 1, i_b0->current_length);
164 icv_size = sa0->integ_trunc_size;
165 if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
169 u8 *icv = ah0->auth_data;
170 memcpy (digest, icv, icv_size);
171 clib_memset (icv, 0, icv_size);
175 ip_version_traffic_class_and_flow_label =
176 ih6->ip_version_traffic_class_and_flow_label;
177 hop_limit = ih6->hop_limit;
178 ih6->ip_version_traffic_class_and_flow_label = 0x60;
180 nexthdr = ah0->nexthdr;
182 ah_calc_icv_padding_len (icv_size, 1 /* is_ipv6 */ );
191 ih4->flags_and_fragment_offset = 0;
193 ah_calc_icv_padding_len (icv_size, 0 /* is_ipv6 */ );
195 hmac_calc (vm, sa0, (u8 *) ih4, i_b0->current_length, sig);
197 if (PREDICT_FALSE (memcmp (digest, sig, icv_size)))
199 i_b0->error = node->errors[AH_DECRYPT_ERROR_INTEG_ERROR];
203 ipsec_sa_anti_replay_advance (sa0, &ah0->seq_no);
206 vlib_buffer_advance (i_b0,
207 ip_hdr_size + sizeof (ah_header_t) + icv_size +
209 i_b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
211 if (PREDICT_TRUE (ipsec_sa_is_set_IS_TUNNEL (sa0)))
213 if (PREDICT_TRUE (ah0->nexthdr == IP_PROTOCOL_IP_IN_IP))
214 next0 = AH_DECRYPT_NEXT_IP4_INPUT;
215 else if (ah0->nexthdr == IP_PROTOCOL_IPV6)
216 next0 = AH_DECRYPT_NEXT_IP6_INPUT;
220 node->errors[AH_DECRYPT_ERROR_DECRYPTION_FAILED];
225 { /* transport mode */
228 vlib_buffer_advance (i_b0, -sizeof (ip6_header_t));
229 oh6 = vlib_buffer_get_current (i_b0);
230 memmove (oh6, ih6, sizeof (ip6_header_t));
232 next0 = AH_DECRYPT_NEXT_IP6_INPUT;
233 oh6->protocol = nexthdr;
234 oh6->hop_limit = hop_limit;
235 oh6->ip_version_traffic_class_and_flow_label =
236 ip_version_traffic_class_and_flow_label;
237 oh6->payload_length =
238 clib_host_to_net_u16 (vlib_buffer_length_in_chain
239 (vm, i_b0) - sizeof (ip6_header_t));
243 vlib_buffer_advance (i_b0, -sizeof (ip4_header_t));
244 oh4 = vlib_buffer_get_current (i_b0);
245 memmove (oh4, ih4, sizeof (ip4_header_t));
247 next0 = AH_DECRYPT_NEXT_IP4_INPUT;
248 oh4->ip_version_and_header_length = 0x45;
249 oh4->fragment_id = 0;
250 oh4->flags_and_fragment_offset = 0;
251 oh4->protocol = ah0->nexthdr;
253 clib_host_to_net_u16 (vlib_buffer_length_in_chain
257 oh4->checksum = ip4_header_checksum (oh4);
261 /* for IPSec-GRE tunnel next node is ipsec-gre-input */
262 if (PREDICT_FALSE (ipsec_sa_is_set_IS_GRE (sa0)))
263 next0 = AH_DECRYPT_NEXT_IPSEC_GRE_INPUT;
265 vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
267 if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
269 i_b0->flags |= VLIB_BUFFER_IS_TRACED;
270 ah_decrypt_trace_t *tr =
271 vlib_add_trace (vm, node, i_b0, sizeof (*tr));
272 tr->integ_alg = sa0->integ_alg;
275 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
276 n_left_to_next, i_bi0, next0);
278 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
280 vlib_node_increment_counter (vm, node->node_index, AH_DECRYPT_ERROR_RX_PKTS,
281 from_frame->n_vectors);
283 return from_frame->n_vectors;
286 VLIB_NODE_FN (ah4_decrypt_node) (vlib_main_t * vm,
287 vlib_node_runtime_t * node,
288 vlib_frame_t * from_frame)
290 return ah_decrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
294 VLIB_REGISTER_NODE (ah4_decrypt_node) = {
295 .name = "ah4-decrypt",
296 .vector_size = sizeof (u32),
297 .format_trace = format_ah_decrypt_trace,
298 .type = VLIB_NODE_TYPE_INTERNAL,
300 .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
301 .error_strings = ah_decrypt_error_strings,
303 .n_next_nodes = AH_DECRYPT_N_NEXT,
305 #define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
306 foreach_ah_decrypt_next
312 VLIB_NODE_FN (ah6_decrypt_node) (vlib_main_t * vm,
313 vlib_node_runtime_t * node,
314 vlib_frame_t * from_frame)
316 return ah_decrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
320 VLIB_REGISTER_NODE (ah6_decrypt_node) = {
321 .name = "ah6-decrypt",
322 .vector_size = sizeof (u32),
323 .format_trace = format_ah_decrypt_trace,
324 .type = VLIB_NODE_TYPE_INTERNAL,
326 .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
327 .error_strings = ah_decrypt_error_strings,
329 .n_next_nodes = AH_DECRYPT_N_NEXT,
331 #define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
332 foreach_ah_decrypt_next
339 * fd.io coding-style-patch-verification: ON
342 * eval: (c-set-style "gnu")