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_aes_cbc (ipsec_crypto_alg_t alg,
85 u8 * in, u8 * out, size_t in_len, u8 * key, u8 * iv)
87 esp_main_t *em = &esp_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->esp_crypto_algs[alg].type == 0))
103 (alg != em->per_thread_data[thread_index].last_decrypt_alg))
105 cipher = em->esp_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_node_fn (vlib_main_t * vm,
117 vlib_node_runtime_t * node, vlib_frame_t * from_frame)
119 u32 n_left_from, *from, next_index, *to_next;
120 ipsec_main_t *im = &ipsec_main;
121 esp_main_t *em = &esp_main;
123 from = vlib_frame_vector_args (from_frame);
124 n_left_from = from_frame->n_vectors;
125 u32 thread_index = vlib_get_thread_index ();
127 ipsec_alloc_empty_buffers (vm, im);
129 u32 *empty_buffers = im->empty_buffers[thread_index];
131 if (PREDICT_FALSE (vec_len (empty_buffers) < n_left_from))
133 vlib_node_increment_counter (vm, esp_decrypt_node.index,
134 ESP_DECRYPT_ERROR_NO_BUFFER, n_left_from);
135 goto free_buffers_and_exit;
138 next_index = node->cached_next_index;
140 while (n_left_from > 0)
144 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
146 while (n_left_from > 0 && n_left_to_next > 0)
148 u32 i_bi0, o_bi0 = (u32) ~ 0, next0;
150 vlib_buffer_t *o_b0 = 0;
155 ip4_header_t *ih4 = 0, *oh4 = 0;
156 ip6_header_t *ih6 = 0, *oh6 = 0;
158 u8 transport_ip6 = 0;
166 next0 = ESP_DECRYPT_NEXT_DROP;
168 i_b0 = vlib_get_buffer (vm, i_bi0);
169 esp0 = vlib_buffer_get_current (i_b0);
171 sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
172 sa0 = pool_elt_at_index (im->sad, sa_index0);
174 seq = clib_host_to_net_u32 (esp0->seq);
176 /* anti-replay check */
177 if (sa0->use_anti_replay)
181 if (PREDICT_TRUE (sa0->use_esn))
182 rv = esp_replay_check_esn (sa0, seq);
184 rv = esp_replay_check (sa0, seq);
186 if (PREDICT_FALSE (rv))
188 clib_warning ("anti-replay SPI %u seq %u", sa0->spi, seq);
189 vlib_node_increment_counter (vm, esp_decrypt_node.index,
190 ESP_DECRYPT_ERROR_REPLAY, 1);
198 sa0->total_data_size += i_b0->current_length;
200 if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
203 int icv_size = em->esp_integ_algs[sa0->integ_alg].trunc_size;
204 memset (sig, 0, sizeof (sig));
206 vlib_buffer_get_current (i_b0) + i_b0->current_length -
208 i_b0->current_length -= icv_size;
210 hmac_calc (sa0->integ_alg, sa0->integ_key, sa0->integ_key_len,
211 (u8 *) esp0, i_b0->current_length, sig, sa0->use_esn,
214 if (PREDICT_FALSE (memcmp (icv, sig, icv_size)))
216 vlib_node_increment_counter (vm, esp_decrypt_node.index,
217 ESP_DECRYPT_ERROR_INTEG_ERROR,
226 if (PREDICT_TRUE (sa0->use_anti_replay))
228 if (PREDICT_TRUE (sa0->use_esn))
229 esp_replay_advance_esn (sa0, seq);
231 esp_replay_advance (sa0, seq);
234 /* grab free buffer */
235 uword last_empty_buffer = vec_len (empty_buffers) - 1;
236 o_bi0 = empty_buffers[last_empty_buffer];
239 o_b0 = vlib_get_buffer (vm, o_bi0);
240 vlib_prefetch_buffer_with_index (vm,
241 empty_buffers[last_empty_buffer -
243 _vec_len (empty_buffers) = last_empty_buffer;
245 /* add old buffer to the recycle list */
246 vec_add1 (recycle, i_bi0);
248 if (sa0->crypto_alg >= IPSEC_CRYPTO_ALG_AES_CBC_128 &&
249 sa0->crypto_alg <= IPSEC_CRYPTO_ALG_AES_CBC_256)
251 const int BLOCK_SIZE = 16;
252 const int IV_SIZE = 16;
257 (i_b0->current_length - sizeof (esp_header_t) -
258 IV_SIZE) / BLOCK_SIZE;
260 o_b0->current_data = sizeof (ethernet_header_t);
263 if (PREDICT_FALSE (!sa0->is_tunnel && !sa0->is_tunnel_ip6))
267 (ip4_header_t *) (i_b0->data +
268 sizeof (ethernet_header_t));
270 ((ih4->ip_version_and_header_length & 0xF0) != 0x40))
273 ((ih4->ip_version_and_header_length & 0xF0) ==
277 ip_hdr_size = sizeof (ip6_header_t);
279 (ip6_header_t *) (i_b0->data +
280 sizeof (ethernet_header_t));
281 oh6 = vlib_buffer_get_current (o_b0);
285 vlib_node_increment_counter (vm,
286 esp_decrypt_node.index,
287 ESP_DECRYPT_ERROR_NOT_IP,
295 oh4 = vlib_buffer_get_current (o_b0);
296 ip_hdr_size = sizeof (ip4_header_t);
300 esp_decrypt_aes_cbc (sa0->crypto_alg,
301 esp0->data + IV_SIZE,
302 (u8 *) vlib_buffer_get_current (o_b0) +
303 ip_hdr_size, BLOCK_SIZE * blocks,
304 sa0->crypto_key, esp0->data);
306 o_b0->current_length = (blocks * 16) - 2 + ip_hdr_size;
307 o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
309 (esp_footer_t *) ((u8 *) vlib_buffer_get_current (o_b0) +
310 o_b0->current_length);
311 o_b0->current_length -= f0->pad_length;
314 if (PREDICT_TRUE (tunnel_mode))
316 if (PREDICT_TRUE (f0->next_header == IP_PROTOCOL_IP_IN_IP))
318 next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
319 oh4 = vlib_buffer_get_current (o_b0);
321 else if (f0->next_header == IP_PROTOCOL_IPV6)
322 next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
325 clib_warning ("next header: 0x%x", f0->next_header);
326 vlib_node_increment_counter (vm, esp_decrypt_node.index,
327 ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
336 if (PREDICT_FALSE (transport_ip6))
338 next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
339 oh6->ip_version_traffic_class_and_flow_label =
340 ih6->ip_version_traffic_class_and_flow_label;
341 oh6->protocol = f0->next_header;
342 oh6->hop_limit = ih6->hop_limit;
343 oh6->src_address.as_u64[0] = ih6->src_address.as_u64[0];
344 oh6->src_address.as_u64[1] = ih6->src_address.as_u64[1];
345 oh6->dst_address.as_u64[0] = ih6->dst_address.as_u64[0];
346 oh6->dst_address.as_u64[1] = ih6->dst_address.as_u64[1];
347 oh6->payload_length =
348 clib_host_to_net_u16 (vlib_buffer_length_in_chain
350 o_b0) - sizeof (ip6_header_t));
354 next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
355 oh4->ip_version_and_header_length = 0x45;
357 oh4->fragment_id = 0;
358 oh4->flags_and_fragment_offset = 0;
360 oh4->protocol = f0->next_header;
361 oh4->src_address.as_u32 = ih4->src_address.as_u32;
362 oh4->dst_address.as_u32 = ih4->dst_address.as_u32;
364 clib_host_to_net_u16 (vlib_buffer_length_in_chain
366 oh4->checksum = ip4_header_checksum (oh4);
370 /* for IPSec-GRE tunnel next node is ipsec-gre-input */
372 ((vnet_buffer (i_b0)->ipsec.flags) &
373 IPSEC_FLAG_IPSEC_GRE_TUNNEL))
374 next0 = ESP_DECRYPT_NEXT_IPSEC_GRE_INPUT;
376 vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
377 vnet_buffer (o_b0)->sw_if_index[VLIB_RX] =
378 vnet_buffer (i_b0)->sw_if_index[VLIB_RX];
382 if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
386 o_b0->flags |= VLIB_BUFFER_IS_TRACED;
387 o_b0->trace_index = i_b0->trace_index;
388 esp_decrypt_trace_t *tr =
389 vlib_add_trace (vm, node, o_b0, sizeof (*tr));
390 tr->crypto_alg = sa0->crypto_alg;
391 tr->integ_alg = sa0->integ_alg;
395 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
396 n_left_to_next, o_bi0, next0);
398 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
400 vlib_node_increment_counter (vm, esp_decrypt_node.index,
401 ESP_DECRYPT_ERROR_RX_PKTS,
402 from_frame->n_vectors);
404 free_buffers_and_exit:
406 vlib_buffer_free (vm, recycle, vec_len (recycle));
408 return from_frame->n_vectors;
413 VLIB_REGISTER_NODE (esp_decrypt_node) = {
414 .function = esp_decrypt_node_fn,
415 .name = "esp-decrypt",
416 .vector_size = sizeof (u32),
417 .format_trace = format_esp_decrypt_trace,
418 .type = VLIB_NODE_TYPE_INTERNAL,
420 .n_errors = ARRAY_LEN(esp_decrypt_error_strings),
421 .error_strings = esp_decrypt_error_strings,
423 .n_next_nodes = ESP_DECRYPT_N_NEXT,
425 #define _(s,n) [ESP_DECRYPT_NEXT_##s] = n,
426 foreach_esp_decrypt_next
432 VLIB_NODE_FUNCTION_MULTIARCH (esp_decrypt_node, esp_decrypt_node_fn)
434 * fd.io coding-style-patch-verification: ON
437 * eval: (c-set-style "gnu")