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")
32 #define _(v, s) AH_DECRYPT_NEXT_##v,
35 foreach_ah_decrypt_next
40 #define foreach_ah_decrypt_error \
41 _ (RX_PKTS, "AH pkts received") \
42 _ (DECRYPTION_FAILED, "AH decryption failed") \
43 _ (INTEG_ERROR, "Integrity check failed") \
44 _ (NO_TAIL_SPACE, "not enough buffer tail space (dropped)") \
45 _ (DROP_FRAGMENTS, "IP fragments drop") \
46 _ (REPLAY, "SA replayed packet")
50 #define _(sym,str) AH_DECRYPT_ERROR_##sym,
51 foreach_ah_decrypt_error
56 static char *ah_decrypt_error_strings[] = {
57 #define _(sym,string) string,
58 foreach_ah_decrypt_error
64 ipsec_integ_alg_t integ_alg;
68 /* packet trace format function */
70 format_ah_decrypt_trace (u8 * s, va_list * args)
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_decrypt_trace_t *t = va_arg (*args, ah_decrypt_trace_t *);
76 s = format (s, "ah: integrity %U seq-num %d",
77 format_ipsec_integ_alg, t->integ_alg, t->seq_num);
89 u32 ip_version_traffic_class_and_flow_label;
105 } ah_decrypt_packet_data_t;
107 static_always_inline void
108 ah_process_ops (vlib_main_t * vm, vlib_node_runtime_t * node,
109 vnet_crypto_op_t * ops, vlib_buffer_t * b[], u16 * nexts)
111 u32 n_fail, n_ops = vec_len (ops);
112 vnet_crypto_op_t *op = ops;
117 n_fail = n_ops - vnet_crypto_process_ops (vm, op, n_ops);
121 ASSERT (op - ops < n_ops);
123 if (op->status != VNET_CRYPTO_OP_STATUS_COMPLETED)
125 u32 bi = op->user_data;
126 b[bi]->error = node->errors[AH_DECRYPT_ERROR_INTEG_ERROR];
127 nexts[bi] = AH_DECRYPT_NEXT_DROP;
135 ah_decrypt_inline (vlib_main_t * vm,
136 vlib_node_runtime_t * node, vlib_frame_t * from_frame,
140 u32 thread_index = vm->thread_index;
141 u16 buffer_data_size = vlib_buffer_get_default_data_size (vm);
142 ah_decrypt_packet_data_t pkt_data[VLIB_FRAME_SIZE], *pd = pkt_data;
143 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
144 u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
145 ipsec_main_t *im = &ipsec_main;
146 ipsec_per_thread_data_t *ptd = vec_elt_at_index (im->ptd, thread_index);
147 from = vlib_frame_vector_args (from_frame);
148 n_left = from_frame->n_vectors;
150 u32 current_sa_index = ~0, current_sa_bytes = 0, current_sa_pkts = 0;
152 clib_memset (pkt_data, 0, VLIB_FRAME_SIZE * sizeof (pkt_data[0]));
153 vlib_get_buffers (vm, from, b, n_left);
154 clib_memset_u16 (nexts, -1, n_left);
155 vec_reset_length (ptd->integ_ops);
163 if (vnet_buffer (b[0])->ipsec.sad_index != current_sa_index)
165 if (current_sa_index != ~0)
166 vlib_increment_combined_counter (&ipsec_sa_counters, thread_index,
170 current_sa_index = vnet_buffer (b[0])->ipsec.sad_index;
171 sa0 = pool_elt_at_index (im->sad, current_sa_index);
173 current_sa_bytes = current_sa_pkts = 0;
174 vlib_prefetch_combined_counter (&ipsec_sa_counters,
175 thread_index, current_sa_index);
178 pd->sa_index = current_sa_index;
180 ih4 = vlib_buffer_get_current (b[0]);
181 ih6 = vlib_buffer_get_current (b[0]);
182 pd->current_data = b[0]->current_data;
186 ip6_ext_header_t *prev = NULL;
188 ip6_ext_header_find (vm, b[0], ih6, IP_PROTOCOL_IPSEC_AH, &prev);
189 pd->ip_hdr_size = sizeof (ip6_header_t);
190 ASSERT ((u8 *) ah0 - (u8 *) ih6 == pd->ip_hdr_size);
194 if (ip4_is_fragment (ih4))
196 b[0]->error = node->errors[AH_DECRYPT_ERROR_DROP_FRAGMENTS];
197 next[0] = AH_DECRYPT_NEXT_DROP;
200 pd->ip_hdr_size = ip4_header_bytes (ih4);
201 ah0 = (ah_header_t *) ((u8 *) ih4 + pd->ip_hdr_size);
204 pd->seq = clib_host_to_net_u32 (ah0->seq_no);
206 /* anti-replay check */
207 if (ipsec_sa_anti_replay_check (sa0, pd->seq))
209 b[0]->error = node->errors[AH_DECRYPT_ERROR_REPLAY];
210 next[0] = AH_DECRYPT_NEXT_DROP;
214 current_sa_bytes += b[0]->current_length;
215 current_sa_pkts += 1;
217 pd->icv_size = sa0->integ_icv_size;
218 pd->nexthdr_cached = ah0->nexthdr;
219 if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
221 if (PREDICT_FALSE (ipsec_sa_is_set_USE_ESN (sa0) &&
222 pd->current_data + b[0]->current_length
223 + sizeof (u32) > buffer_data_size))
225 b[0]->error = node->errors[AH_DECRYPT_ERROR_NO_TAIL_SPACE];
226 next[0] = AH_DECRYPT_NEXT_DROP;
230 vnet_crypto_op_t *op;
231 vec_add2_aligned (ptd->integ_ops, op, 1, CLIB_CACHE_LINE_BYTES);
232 vnet_crypto_op_init (op, sa0->integ_op_id);
234 op->src = (u8 *) ih4;
235 op->len = b[0]->current_length;
236 op->digest = (u8 *) ih4 - pd->icv_size;
237 op->flags = VNET_CRYPTO_OP_FLAG_HMAC_CHECK;
238 op->digest_len = pd->icv_size;
239 op->key_index = sa0->integ_key_index;
240 op->user_data = b - bufs;
241 if (ipsec_sa_is_set_USE_ESN (sa0))
243 u32 seq_hi = clib_host_to_net_u32 (sa0->seq_hi);
245 op->len += sizeof (seq_hi);
246 clib_memcpy (op->src + b[0]->current_length, &seq_hi,
249 clib_memcpy (op->digest, ah0->auth_data, pd->icv_size);
250 clib_memset (ah0->auth_data, 0, pd->icv_size);
254 pd->ip_version_traffic_class_and_flow_label =
255 ih6->ip_version_traffic_class_and_flow_label;
256 pd->hop_limit = ih6->hop_limit;
257 ih6->ip_version_traffic_class_and_flow_label = 0x60;
259 pd->nexthdr = ah0->nexthdr;
260 pd->icv_padding_len =
261 ah_calc_icv_padding_len (pd->icv_size, 1 /* is_ipv6 */ );
270 pd->icv_padding_len =
271 ah_calc_icv_padding_len (pd->icv_size, 0 /* is_ipv6 */ );
282 n_left = from_frame->n_vectors;
287 vlib_node_increment_counter (vm, node->node_index, AH_DECRYPT_ERROR_RX_PKTS,
289 vlib_increment_combined_counter (&ipsec_sa_counters, thread_index,
290 current_sa_index, current_sa_pkts,
293 ah_process_ops (vm, node, ptd->integ_ops, bufs, nexts);
300 if (next[0] < AH_DECRYPT_N_NEXT)
303 sa0 = vec_elt_at_index (im->sad, pd->sa_index);
305 if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
307 /* redo the anit-reply check. see esp_decrypt for details */
308 if (ipsec_sa_anti_replay_check (sa0, pd->seq))
310 b[0]->error = node->errors[AH_DECRYPT_ERROR_REPLAY];
311 next[0] = AH_DECRYPT_NEXT_DROP;
314 ipsec_sa_anti_replay_advance (sa0, pd->seq);
317 u16 ah_hdr_len = sizeof (ah_header_t) + pd->icv_size
318 + pd->icv_padding_len;
319 vlib_buffer_advance (b[0], pd->ip_hdr_size + ah_hdr_len);
320 b[0]->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
322 if (PREDICT_TRUE (ipsec_sa_is_set_IS_TUNNEL (sa0)))
324 if (PREDICT_TRUE (pd->nexthdr_cached == IP_PROTOCOL_IP_IN_IP))
325 next[0] = AH_DECRYPT_NEXT_IP4_INPUT;
326 else if (pd->nexthdr_cached == IP_PROTOCOL_IPV6)
327 next[0] = AH_DECRYPT_NEXT_IP6_INPUT;
330 b[0]->error = node->errors[AH_DECRYPT_ERROR_DECRYPTION_FAILED];
331 next[0] = AH_DECRYPT_NEXT_DROP;
336 { /* transport mode */
339 vlib_buffer_advance (b[0], -sizeof (ip6_header_t));
340 oh6 = vlib_buffer_get_current (b[0]);
341 if (ah_hdr_len >= sizeof (ip6_header_t))
342 clib_memcpy (oh6, b[0]->data + pd->current_data,
343 sizeof (ip6_header_t));
345 memmove (oh6, b[0]->data + pd->current_data,
346 sizeof (ip6_header_t));
348 next[0] = AH_DECRYPT_NEXT_IP6_INPUT;
349 oh6->protocol = pd->nexthdr;
350 oh6->hop_limit = pd->hop_limit;
351 oh6->ip_version_traffic_class_and_flow_label =
352 pd->ip_version_traffic_class_and_flow_label;
353 oh6->payload_length =
354 clib_host_to_net_u16 (vlib_buffer_length_in_chain
355 (vm, b[0]) - sizeof (ip6_header_t));
359 vlib_buffer_advance (b[0], -sizeof (ip4_header_t));
360 oh4 = vlib_buffer_get_current (b[0]);
361 if (ah_hdr_len >= sizeof (ip4_header_t))
362 clib_memcpy (oh4, b[0]->data + pd->current_data,
363 sizeof (ip4_header_t));
365 memmove (oh4, b[0]->data + pd->current_data,
366 sizeof (ip4_header_t));
368 next[0] = AH_DECRYPT_NEXT_IP4_INPUT;
369 oh4->ip_version_and_header_length = 0x45;
370 oh4->fragment_id = 0;
371 oh4->flags_and_fragment_offset = 0;
372 oh4->protocol = pd->nexthdr_cached;
374 clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b[0]));
377 oh4->checksum = ip4_header_checksum (oh4);
381 vnet_buffer (b[0])->sw_if_index[VLIB_TX] = (u32) ~ 0;
383 if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
385 sa0 = pool_elt_at_index (im->sad,
386 vnet_buffer (b[0])->ipsec.sad_index);
387 ah_decrypt_trace_t *tr =
388 vlib_add_trace (vm, node, b[0], sizeof (*tr));
389 tr->integ_alg = sa0->integ_alg;
390 tr->seq_num = pd->seq;
399 n_left = from_frame->n_vectors;
400 vlib_buffer_enqueue_to_next (vm, node, from, nexts, n_left);
405 VLIB_NODE_FN (ah4_decrypt_node) (vlib_main_t * vm,
406 vlib_node_runtime_t * node,
407 vlib_frame_t * from_frame)
409 return ah_decrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
413 VLIB_REGISTER_NODE (ah4_decrypt_node) = {
414 .name = "ah4-decrypt",
415 .vector_size = sizeof (u32),
416 .format_trace = format_ah_decrypt_trace,
417 .type = VLIB_NODE_TYPE_INTERNAL,
419 .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
420 .error_strings = ah_decrypt_error_strings,
422 .n_next_nodes = AH_DECRYPT_N_NEXT,
424 #define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
425 foreach_ah_decrypt_next
431 VLIB_NODE_FN (ah6_decrypt_node) (vlib_main_t * vm,
432 vlib_node_runtime_t * node,
433 vlib_frame_t * from_frame)
435 return ah_decrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
439 VLIB_REGISTER_NODE (ah6_decrypt_node) = {
440 .name = "ah6-decrypt",
441 .vector_size = sizeof (u32),
442 .format_trace = format_ah_decrypt_trace,
443 .type = VLIB_NODE_TYPE_INTERNAL,
445 .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
446 .error_strings = ah_decrypt_error_strings,
448 .n_next_nodes = AH_DECRYPT_N_NEXT,
450 #define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
451 foreach_ah_decrypt_next
458 * fd.io coding-style-patch-verification: ON
461 * eval: (c-set-style "gnu")