2 * esp_decrypt.c : IPSec ESP 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>
25 #define foreach_esp_decrypt_next \
26 _(DROP, "error-drop") \
27 _(IP4_INPUT, "ip4-input") \
28 _(IP6_INPUT, "ip6-input") \
29 _(IPSEC_GRE_INPUT, "ipsec-gre-input")
31 #define _(v, s) ESP_DECRYPT_NEXT_##v,
34 foreach_esp_decrypt_next
40 #define foreach_esp_decrypt_error \
41 _(RX_PKTS, "ESP pkts received") \
42 _(NO_BUFFER, "No buffer (packed dropped)") \
43 _(DECRYPTION_FAILED, "ESP decryption failed") \
44 _(INTEG_ERROR, "Integrity check failed") \
45 _(REPLAY, "SA replayed packet") \
46 _(NOT_IP, "Not IP packet (dropped)")
51 #define _(sym,str) ESP_DECRYPT_ERROR_##sym,
52 foreach_esp_decrypt_error
55 } esp_decrypt_error_t;
57 static char *esp_decrypt_error_strings[] = {
58 #define _(sym,string) string,
59 foreach_esp_decrypt_error
65 ipsec_crypto_alg_t crypto_alg;
66 ipsec_integ_alg_t integ_alg;
67 } esp_decrypt_trace_t;
69 /* packet trace format function */
71 format_esp_decrypt_trace (u8 * s, va_list * args)
73 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
74 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
75 esp_decrypt_trace_t *t = va_arg (*args, esp_decrypt_trace_t *);
77 s = format (s, "esp: crypto %U integrity %U",
78 format_ipsec_crypto_alg, t->crypto_alg,
79 format_ipsec_integ_alg, t->integ_alg);
84 esp_decrypt_cbc (ipsec_crypto_alg_t alg,
85 u8 * in, u8 * out, size_t in_len, u8 * key, u8 * iv)
87 ipsec_proto_main_t *em = &ipsec_proto_main;
88 u32 thread_index = vlib_get_thread_index ();
89 #if OPENSSL_VERSION_NUMBER >= 0x10100000L
90 EVP_CIPHER_CTX *ctx = em->per_thread_data[thread_index].decrypt_ctx;
92 EVP_CIPHER_CTX *ctx = &(em->per_thread_data[thread_index].decrypt_ctx);
94 const EVP_CIPHER *cipher = NULL;
97 ASSERT (alg < IPSEC_CRYPTO_N_ALG);
99 if (PREDICT_FALSE (em->ipsec_proto_main_crypto_algs[alg].type == 0))
103 (alg != em->per_thread_data[thread_index].last_decrypt_alg))
105 cipher = em->ipsec_proto_main_crypto_algs[alg].type;
106 em->per_thread_data[thread_index].last_decrypt_alg = alg;
109 EVP_DecryptInit_ex (ctx, cipher, NULL, key, iv);
111 EVP_DecryptUpdate (ctx, out, &out_len, in, in_len);
112 EVP_DecryptFinal_ex (ctx, out + out_len, &out_len);
116 esp_decrypt_inline (vlib_main_t * vm,
117 vlib_node_runtime_t * node, vlib_frame_t * from_frame,
120 u32 n_left_from, *from, next_index, *to_next;
121 ipsec_main_t *im = &ipsec_main;
122 ipsec_proto_main_t *em = &ipsec_proto_main;
124 from = vlib_frame_vector_args (from_frame);
125 n_left_from = from_frame->n_vectors;
126 u32 thread_index = vlib_get_thread_index ();
128 ipsec_alloc_empty_buffers (vm, im);
130 u32 *empty_buffers = im->empty_buffers[thread_index];
132 if (PREDICT_FALSE (vec_len (empty_buffers) < n_left_from))
135 vlib_node_increment_counter (vm, esp6_decrypt_node.index,
136 ESP_DECRYPT_ERROR_NO_BUFFER,
139 vlib_node_increment_counter (vm, esp4_decrypt_node.index,
140 ESP_DECRYPT_ERROR_NO_BUFFER,
142 goto free_buffers_and_exit;
145 next_index = node->cached_next_index;
147 while (n_left_from > 0)
151 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
153 while (n_left_from > 0 && n_left_to_next > 0)
155 u32 i_bi0, o_bi0 = (u32) ~ 0, next0;
157 vlib_buffer_t *o_b0 = 0;
162 ip4_header_t *ih4 = 0, *oh4 = 0;
163 ip6_header_t *ih6 = 0, *oh6 = 0;
171 next0 = ESP_DECRYPT_NEXT_DROP;
173 i_b0 = vlib_get_buffer (vm, i_bi0);
174 esp0 = vlib_buffer_get_current (i_b0);
176 sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
177 sa0 = pool_elt_at_index (im->sad, sa_index0);
179 seq = clib_host_to_net_u32 (esp0->seq);
181 /* anti-replay check */
182 if (sa0->use_anti_replay)
186 if (PREDICT_TRUE (sa0->use_esn))
187 rv = esp_replay_check_esn (sa0, seq);
189 rv = esp_replay_check (sa0, seq);
191 if (PREDICT_FALSE (rv))
193 clib_warning ("anti-replay SPI %u seq %u", sa0->spi, seq);
195 vlib_node_increment_counter (vm,
196 esp6_decrypt_node.index,
197 ESP_DECRYPT_ERROR_REPLAY, 1);
199 vlib_node_increment_counter (vm,
200 esp4_decrypt_node.index,
201 ESP_DECRYPT_ERROR_REPLAY, 1);
209 sa0->total_data_size += i_b0->current_length;
211 if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
215 em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
216 clib_memset (sig, 0, sizeof (sig));
218 vlib_buffer_get_current (i_b0) + i_b0->current_length -
220 i_b0->current_length -= icv_size;
222 hmac_calc (sa0->integ_alg, sa0->integ_key, sa0->integ_key_len,
223 (u8 *) esp0, i_b0->current_length, sig, sa0->use_esn,
226 if (PREDICT_FALSE (memcmp (icv, sig, icv_size)))
229 vlib_node_increment_counter (vm,
230 esp6_decrypt_node.index,
231 ESP_DECRYPT_ERROR_INTEG_ERROR,
234 vlib_node_increment_counter (vm,
235 esp4_decrypt_node.index,
236 ESP_DECRYPT_ERROR_INTEG_ERROR,
245 if (PREDICT_TRUE (sa0->use_anti_replay))
247 if (PREDICT_TRUE (sa0->use_esn))
248 esp_replay_advance_esn (sa0, seq);
250 esp_replay_advance (sa0, seq);
253 /* grab free buffer */
254 uword last_empty_buffer = vec_len (empty_buffers) - 1;
255 o_bi0 = empty_buffers[last_empty_buffer];
258 o_b0 = vlib_get_buffer (vm, o_bi0);
259 vlib_prefetch_buffer_with_index (vm,
260 empty_buffers[last_empty_buffer -
262 _vec_len (empty_buffers) = last_empty_buffer;
264 /* add old buffer to the recycle list */
265 vec_add1 (recycle, i_bi0);
267 if ((sa0->crypto_alg >= IPSEC_CRYPTO_ALG_AES_CBC_128 &&
268 sa0->crypto_alg <= IPSEC_CRYPTO_ALG_AES_CBC_256) ||
269 (sa0->crypto_alg >= IPSEC_CRYPTO_ALG_DES_CBC &&
270 sa0->crypto_alg <= IPSEC_CRYPTO_ALG_3DES_CBC))
272 const int BLOCK_SIZE =
273 em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].block_size;;
275 em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size;
280 (i_b0->current_length - sizeof (esp_header_t) -
281 IV_SIZE) / BLOCK_SIZE;
283 o_b0->current_data = sizeof (ethernet_header_t);
286 if (PREDICT_FALSE (!sa0->is_tunnel && !sa0->is_tunnel_ip6))
293 (ip6_header_t *) ((u8 *) esp0 -
294 sizeof (ip6_header_t));
295 ip_hdr_size = sizeof (ip6_header_t);
296 oh6 = vlib_buffer_get_current (o_b0);
301 (ip4_header_t *) ((u8 *) esp0 -
302 sizeof (ip4_header_t));
303 oh4 = vlib_buffer_get_current (o_b0);
304 ip_hdr_size = sizeof (ip4_header_t);
308 esp_decrypt_cbc (sa0->crypto_alg,
309 esp0->data + IV_SIZE,
310 (u8 *) vlib_buffer_get_current (o_b0) +
311 ip_hdr_size, BLOCK_SIZE * blocks,
312 sa0->crypto_key, esp0->data);
314 o_b0->current_length = (blocks * BLOCK_SIZE) - 2 + ip_hdr_size;
315 o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
317 (esp_footer_t *) ((u8 *) vlib_buffer_get_current (o_b0) +
318 o_b0->current_length);
319 o_b0->current_length -= f0->pad_length;
322 if (PREDICT_TRUE (tunnel_mode))
324 if (PREDICT_TRUE (f0->next_header == IP_PROTOCOL_IP_IN_IP))
326 next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
327 oh4 = vlib_buffer_get_current (o_b0);
329 else if (f0->next_header == IP_PROTOCOL_IPV6)
330 next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
333 clib_warning ("next header: 0x%x", f0->next_header);
335 vlib_node_increment_counter (vm,
336 esp6_decrypt_node.index,
337 ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
340 vlib_node_increment_counter (vm,
341 esp4_decrypt_node.index,
342 ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
353 next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
354 oh6->ip_version_traffic_class_and_flow_label =
355 ih6->ip_version_traffic_class_and_flow_label;
356 oh6->protocol = f0->next_header;
357 oh6->hop_limit = ih6->hop_limit;
358 oh6->src_address.as_u64[0] = ih6->src_address.as_u64[0];
359 oh6->src_address.as_u64[1] = ih6->src_address.as_u64[1];
360 oh6->dst_address.as_u64[0] = ih6->dst_address.as_u64[0];
361 oh6->dst_address.as_u64[1] = ih6->dst_address.as_u64[1];
362 oh6->payload_length =
363 clib_host_to_net_u16 (vlib_buffer_length_in_chain
365 o_b0) - sizeof (ip6_header_t));
369 next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
370 oh4->ip_version_and_header_length = 0x45;
372 oh4->fragment_id = 0;
373 oh4->flags_and_fragment_offset = 0;
375 oh4->protocol = f0->next_header;
376 oh4->src_address.as_u32 = ih4->src_address.as_u32;
377 oh4->dst_address.as_u32 = ih4->dst_address.as_u32;
379 clib_host_to_net_u16 (vlib_buffer_length_in_chain
381 oh4->checksum = ip4_header_checksum (oh4);
385 /* for IPSec-GRE tunnel next node is ipsec-gre-input */
387 ((vnet_buffer (i_b0)->ipsec.flags) &
388 IPSEC_FLAG_IPSEC_GRE_TUNNEL))
389 next0 = ESP_DECRYPT_NEXT_IPSEC_GRE_INPUT;
391 vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
392 vnet_buffer (o_b0)->sw_if_index[VLIB_RX] =
393 vnet_buffer (i_b0)->sw_if_index[VLIB_RX];
397 if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
401 o_b0->flags |= VLIB_BUFFER_IS_TRACED;
402 o_b0->trace_index = i_b0->trace_index;
403 esp_decrypt_trace_t *tr =
404 vlib_add_trace (vm, node, o_b0, sizeof (*tr));
405 tr->crypto_alg = sa0->crypto_alg;
406 tr->integ_alg = sa0->integ_alg;
410 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
411 n_left_to_next, o_bi0, next0);
413 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
416 vlib_node_increment_counter (vm, esp6_decrypt_node.index,
417 ESP_DECRYPT_ERROR_RX_PKTS,
418 from_frame->n_vectors);
420 vlib_node_increment_counter (vm, esp4_decrypt_node.index,
421 ESP_DECRYPT_ERROR_RX_PKTS,
422 from_frame->n_vectors);
425 free_buffers_and_exit:
427 vlib_buffer_free (vm, recycle, vec_len (recycle));
429 return from_frame->n_vectors;
433 esp4_decrypt_node_fn (vlib_main_t * vm,
434 vlib_node_runtime_t * node, vlib_frame_t * from_frame)
436 return esp_decrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
440 VLIB_REGISTER_NODE (esp4_decrypt_node) = {
441 .function = esp4_decrypt_node_fn,
442 .name = "esp4-decrypt",
443 .vector_size = sizeof (u32),
444 .format_trace = format_esp_decrypt_trace,
445 .type = VLIB_NODE_TYPE_INTERNAL,
447 .n_errors = ARRAY_LEN(esp_decrypt_error_strings),
448 .error_strings = esp_decrypt_error_strings,
450 .n_next_nodes = ESP_DECRYPT_N_NEXT,
452 #define _(s,n) [ESP_DECRYPT_NEXT_##s] = n,
453 foreach_esp_decrypt_next
459 VLIB_NODE_FUNCTION_MULTIARCH (esp4_decrypt_node, esp4_decrypt_node_fn);
462 esp6_decrypt_node_fn (vlib_main_t * vm,
463 vlib_node_runtime_t * node, vlib_frame_t * from_frame)
465 return esp_decrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
469 VLIB_REGISTER_NODE (esp6_decrypt_node) = {
470 .function = esp6_decrypt_node_fn,
471 .name = "esp6-decrypt",
472 .vector_size = sizeof (u32),
473 .format_trace = format_esp_decrypt_trace,
474 .type = VLIB_NODE_TYPE_INTERNAL,
476 .n_errors = ARRAY_LEN(esp_decrypt_error_strings),
477 .error_strings = esp_decrypt_error_strings,
479 .n_next_nodes = ESP_DECRYPT_N_NEXT,
481 #define _(s,n) [ESP_DECRYPT_NEXT_##s] = n,
482 foreach_esp_decrypt_next
488 VLIB_NODE_FUNCTION_MULTIARCH (esp6_decrypt_node, esp6_decrypt_node_fn);
490 * fd.io coding-style-patch-verification: ON
493 * eval: (c-set-style "gnu")