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 ipsec_proto_main_t *em = &ipsec_proto_main;
88 from = vlib_frame_vector_args (from_frame);
89 n_left_from = from_frame->n_vectors;
92 next_index = node->cached_next_index;
93 thread_index = vm->thread_index;
95 while (n_left_from > 0)
99 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
101 while (n_left_from > 0 && n_left_to_next > 0)
110 ip4_header_t *ih4 = 0, *oh4 = 0;
111 ip6_header_t *ih6 = 0, *oh6 = 0;
115 u32 ip_version_traffic_class_and_flow_label = 0;
118 u8 icv_padding_len = 0;
126 next0 = AH_DECRYPT_NEXT_DROP;
128 i_b0 = vlib_get_buffer (vm, i_bi0);
131 ih4 = vlib_buffer_get_current (i_b0);
132 ih6 = vlib_buffer_get_current (i_b0);
133 sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
134 sa0 = pool_elt_at_index (im->sad, sa_index0);
136 vlib_prefetch_combined_counter (&ipsec_sa_counters,
137 thread_index, sa_index0);
141 ip6_ext_header_t *prev = NULL;
142 ip6_ext_header_find_t (ih6, prev, ah0, IP_PROTOCOL_IPSEC_AH);
143 ip_hdr_size = sizeof (ip6_header_t);
144 ASSERT ((u8 *) ah0 - (u8 *) ih6 == ip_hdr_size);
148 ip_hdr_size = ip4_header_bytes (ih4);
149 ah0 = (ah_header_t *) ((u8 *) ih4 + ip_hdr_size);
152 seq = clib_host_to_net_u32 (ah0->seq_no);
154 /* anti-replay check */
155 if (sa0->use_anti_replay)
159 if (PREDICT_TRUE (sa0->use_esn))
160 rv = esp_replay_check_esn (sa0, seq);
162 rv = esp_replay_check (sa0, seq);
164 if (PREDICT_FALSE (rv))
166 vlib_node_increment_counter (vm, node->node_index,
167 AH_DECRYPT_ERROR_REPLAY, 1);
172 vlib_increment_combined_counter
173 (&ipsec_sa_counters, thread_index, sa_index0,
174 1, i_b0->current_length);
177 em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
178 if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
182 clib_memset (sig, 0, sizeof (sig));
183 clib_memset (digest, 0, sizeof (digest));
184 u8 *icv = ah0->auth_data;
185 memcpy (digest, icv, icv_size);
186 clib_memset (icv, 0, icv_size);
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;
195 nexthdr = ah0->nexthdr;
197 ah_calc_icv_padding_len (icv_size, 1 /* is_ipv6 */ );
206 ih4->flags_and_fragment_offset = 0;
208 ah_calc_icv_padding_len (icv_size, 0 /* is_ipv6 */ );
210 hmac_calc (sa0->integ_alg, sa0->integ_key.data,
211 sa0->integ_key.len, (u8 *) ih4, i_b0->current_length,
212 sig, sa0->use_esn, sa0->seq_hi);
214 if (PREDICT_FALSE (memcmp (digest, sig, icv_size)))
216 vlib_node_increment_counter (vm, node->node_index,
217 AH_DECRYPT_ERROR_INTEG_ERROR,
222 if (PREDICT_TRUE (sa0->use_anti_replay))
224 if (PREDICT_TRUE (sa0->use_esn))
225 esp_replay_advance_esn (sa0, seq);
227 esp_replay_advance (sa0, seq);
232 vlib_buffer_advance (i_b0,
233 ip_hdr_size + sizeof (ah_header_t) + icv_size +
235 i_b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
237 if (PREDICT_TRUE (sa0->is_tunnel))
239 if (PREDICT_TRUE (ah0->nexthdr == IP_PROTOCOL_IP_IN_IP))
240 next0 = AH_DECRYPT_NEXT_IP4_INPUT;
241 else if (ah0->nexthdr == IP_PROTOCOL_IPV6)
242 next0 = AH_DECRYPT_NEXT_IP6_INPUT;
245 vlib_node_increment_counter (vm, node->node_index,
246 AH_DECRYPT_ERROR_DECRYPTION_FAILED,
252 { /* transport mode */
255 vlib_buffer_advance (i_b0, -sizeof (ip6_header_t));
256 oh6 = vlib_buffer_get_current (i_b0);
257 memmove (oh6, ih6, sizeof (ip6_header_t));
259 next0 = AH_DECRYPT_NEXT_IP6_INPUT;
260 oh6->protocol = nexthdr;
261 oh6->hop_limit = hop_limit;
262 oh6->ip_version_traffic_class_and_flow_label =
263 ip_version_traffic_class_and_flow_label;
264 oh6->payload_length =
265 clib_host_to_net_u16 (vlib_buffer_length_in_chain
266 (vm, i_b0) - sizeof (ip6_header_t));
270 vlib_buffer_advance (i_b0, -sizeof (ip4_header_t));
271 oh4 = vlib_buffer_get_current (i_b0);
272 memmove (oh4, ih4, sizeof (ip4_header_t));
274 next0 = AH_DECRYPT_NEXT_IP4_INPUT;
275 oh4->ip_version_and_header_length = 0x45;
276 oh4->fragment_id = 0;
277 oh4->flags_and_fragment_offset = 0;
278 oh4->protocol = ah0->nexthdr;
280 clib_host_to_net_u16 (vlib_buffer_length_in_chain
284 oh4->checksum = ip4_header_checksum (oh4);
288 /* for IPSec-GRE tunnel next node is ipsec-gre-input */
290 ((vnet_buffer (i_b0)->ipsec.flags) &
291 IPSEC_FLAG_IPSEC_GRE_TUNNEL))
292 next0 = AH_DECRYPT_NEXT_IPSEC_GRE_INPUT;
295 vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
297 if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
299 i_b0->flags |= VLIB_BUFFER_IS_TRACED;
300 ah_decrypt_trace_t *tr =
301 vlib_add_trace (vm, node, i_b0, sizeof (*tr));
302 tr->integ_alg = sa0->integ_alg;
305 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
306 n_left_to_next, i_bi0, next0);
308 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
310 vlib_node_increment_counter (vm, node->node_index, AH_DECRYPT_ERROR_RX_PKTS,
311 from_frame->n_vectors);
313 return from_frame->n_vectors;
316 VLIB_NODE_FN (ah4_decrypt_node) (vlib_main_t * vm,
317 vlib_node_runtime_t * node,
318 vlib_frame_t * from_frame)
320 return ah_decrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
324 VLIB_REGISTER_NODE (ah4_decrypt_node) = {
325 .name = "ah4-decrypt",
326 .vector_size = sizeof (u32),
327 .format_trace = format_ah_decrypt_trace,
328 .type = VLIB_NODE_TYPE_INTERNAL,
330 .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
331 .error_strings = ah_decrypt_error_strings,
333 .n_next_nodes = AH_DECRYPT_N_NEXT,
335 #define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
336 foreach_ah_decrypt_next
342 VLIB_NODE_FN (ah6_decrypt_node) (vlib_main_t * vm,
343 vlib_node_runtime_t * node,
344 vlib_frame_t * from_frame)
346 return ah_decrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
350 VLIB_REGISTER_NODE (ah6_decrypt_node) = {
351 .name = "ah6-decrypt",
352 .vector_size = sizeof (u32),
353 .format_trace = format_ah_decrypt_trace,
354 .type = VLIB_NODE_TYPE_INTERNAL,
356 .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
357 .error_strings = ah_decrypt_error_strings,
359 .n_next_nodes = AH_DECRYPT_N_NEXT,
361 #define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
362 foreach_ah_decrypt_next
369 * fd.io coding-style-patch-verification: ON
372 * eval: (c-set-style "gnu")