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 cpu_index = os_get_cpu_number ();
89 EVP_CIPHER_CTX *ctx = &(em->per_thread_data[cpu_index].decrypt_ctx);
90 const EVP_CIPHER *cipher = NULL;
93 ASSERT (alg < IPSEC_CRYPTO_N_ALG);
95 if (PREDICT_FALSE (em->esp_crypto_algs[alg].type == 0))
98 if (PREDICT_FALSE (alg != em->per_thread_data[cpu_index].last_decrypt_alg))
100 cipher = em->esp_crypto_algs[alg].type;
101 em->per_thread_data[cpu_index].last_decrypt_alg = alg;
104 EVP_DecryptInit_ex (ctx, cipher, NULL, key, iv);
106 EVP_DecryptUpdate (ctx, out, &out_len, in, in_len);
107 EVP_DecryptFinal_ex (ctx, out + out_len, &out_len);
111 esp_decrypt_node_fn (vlib_main_t * vm,
112 vlib_node_runtime_t * node, vlib_frame_t * from_frame)
114 u32 n_left_from, *from, next_index, *to_next;
115 ipsec_main_t *im = &ipsec_main;
116 esp_main_t *em = &esp_main;
118 from = vlib_frame_vector_args (from_frame);
119 n_left_from = from_frame->n_vectors;
120 u32 cpu_index = os_get_cpu_number ();
122 ipsec_alloc_empty_buffers (vm, im);
124 u32 *empty_buffers = im->empty_buffers[cpu_index];
126 if (PREDICT_FALSE (vec_len (empty_buffers) < n_left_from))
128 vlib_node_increment_counter (vm, esp_decrypt_node.index,
129 ESP_DECRYPT_ERROR_NO_BUFFER, n_left_from);
130 goto free_buffers_and_exit;
133 next_index = node->cached_next_index;
135 while (n_left_from > 0)
139 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
141 while (n_left_from > 0 && n_left_to_next > 0)
143 u32 i_bi0, o_bi0 = (u32) ~ 0, next0;
145 vlib_buffer_t *o_b0 = 0;
150 ip4_header_t *ih4 = 0, *oh4 = 0;
151 ip6_header_t *ih6 = 0, *oh6 = 0;
153 u8 transport_ip6 = 0;
161 next0 = ESP_DECRYPT_NEXT_DROP;
163 i_b0 = vlib_get_buffer (vm, i_bi0);
164 esp0 = vlib_buffer_get_current (i_b0);
166 sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
167 sa0 = pool_elt_at_index (im->sad, sa_index0);
169 seq = clib_host_to_net_u32 (esp0->seq);
171 /* anti-replay check */
172 if (sa0->use_anti_replay)
176 if (PREDICT_TRUE (sa0->use_esn))
177 rv = esp_replay_check_esn (sa0, seq);
179 rv = esp_replay_check (sa0, seq);
181 if (PREDICT_FALSE (rv))
183 clib_warning ("anti-replay SPI %u seq %u", sa0->spi, seq);
184 vlib_node_increment_counter (vm, esp_decrypt_node.index,
185 ESP_DECRYPT_ERROR_REPLAY, 1);
193 sa0->total_data_size += i_b0->current_length;
195 if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
198 int icv_size = em->esp_integ_algs[sa0->integ_alg].trunc_size;
199 memset (sig, 0, sizeof (sig));
201 vlib_buffer_get_current (i_b0) + i_b0->current_length -
203 i_b0->current_length -= icv_size;
205 hmac_calc (sa0->integ_alg, sa0->integ_key, sa0->integ_key_len,
206 (u8 *) esp0, i_b0->current_length, sig, sa0->use_esn,
209 if (PREDICT_FALSE (memcmp (icv, sig, icv_size)))
211 vlib_node_increment_counter (vm, esp_decrypt_node.index,
212 ESP_DECRYPT_ERROR_INTEG_ERROR,
221 if (PREDICT_TRUE (sa0->use_anti_replay))
223 if (PREDICT_TRUE (sa0->use_esn))
224 esp_replay_advance_esn (sa0, seq);
226 esp_replay_advance (sa0, seq);
229 /* grab free buffer */
230 uword last_empty_buffer = vec_len (empty_buffers) - 1;
231 o_bi0 = empty_buffers[last_empty_buffer];
234 o_b0 = vlib_get_buffer (vm, o_bi0);
235 vlib_prefetch_buffer_with_index (vm,
236 empty_buffers[last_empty_buffer -
238 _vec_len (empty_buffers) = last_empty_buffer;
240 /* add old buffer to the recycle list */
241 vec_add1 (recycle, i_bi0);
243 if (sa0->crypto_alg >= IPSEC_CRYPTO_ALG_AES_CBC_128 &&
244 sa0->crypto_alg <= IPSEC_CRYPTO_ALG_AES_CBC_256)
246 const int BLOCK_SIZE = 16;
247 const int IV_SIZE = 16;
252 (i_b0->current_length - sizeof (esp_header_t) -
253 IV_SIZE) / BLOCK_SIZE;
255 o_b0->current_data = sizeof (ethernet_header_t);
258 if (PREDICT_FALSE (!sa0->is_tunnel && !sa0->is_tunnel_ip6))
262 (ip4_header_t *) (i_b0->data +
263 sizeof (ethernet_header_t));
265 ((ih4->ip_version_and_header_length & 0xF0) != 0x40))
268 ((ih4->ip_version_and_header_length & 0xF0) ==
272 ip_hdr_size = sizeof (ip6_header_t);
274 (ip6_header_t *) (i_b0->data +
275 sizeof (ethernet_header_t));
276 oh6 = vlib_buffer_get_current (o_b0);
280 vlib_node_increment_counter (vm,
281 esp_decrypt_node.index,
282 ESP_DECRYPT_ERROR_NOT_IP,
290 oh4 = vlib_buffer_get_current (o_b0);
291 ip_hdr_size = sizeof (ip4_header_t);
295 esp_decrypt_aes_cbc (sa0->crypto_alg,
296 esp0->data + IV_SIZE,
297 (u8 *) vlib_buffer_get_current (o_b0) +
298 ip_hdr_size, BLOCK_SIZE * blocks,
299 sa0->crypto_key, esp0->data);
301 o_b0->current_length = (blocks * 16) - 2 + ip_hdr_size;
302 o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
304 (esp_footer_t *) ((u8 *) vlib_buffer_get_current (o_b0) +
305 o_b0->current_length);
306 o_b0->current_length -= f0->pad_length;
309 if (PREDICT_TRUE (tunnel_mode))
311 if (PREDICT_TRUE (f0->next_header == IP_PROTOCOL_IP_IN_IP))
313 next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
314 oh4 = vlib_buffer_get_current (o_b0);
316 else if (f0->next_header == IP_PROTOCOL_IPV6)
317 next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
320 clib_warning ("next header: 0x%x", f0->next_header);
321 vlib_node_increment_counter (vm, esp_decrypt_node.index,
322 ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
331 if (PREDICT_FALSE (transport_ip6))
333 next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
334 oh6->ip_version_traffic_class_and_flow_label =
335 ih6->ip_version_traffic_class_and_flow_label;
336 oh6->protocol = f0->next_header;
337 oh6->hop_limit = ih6->hop_limit;
338 oh6->src_address.as_u64[0] = ih6->src_address.as_u64[0];
339 oh6->src_address.as_u64[1] = ih6->src_address.as_u64[1];
340 oh6->dst_address.as_u64[0] = ih6->dst_address.as_u64[0];
341 oh6->dst_address.as_u64[1] = ih6->dst_address.as_u64[1];
342 oh6->payload_length =
343 clib_host_to_net_u16 (vlib_buffer_length_in_chain
345 o_b0) - sizeof (ip6_header_t));
349 next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
350 oh4->ip_version_and_header_length = 0x45;
352 oh4->fragment_id = 0;
353 oh4->flags_and_fragment_offset = 0;
355 oh4->protocol = f0->next_header;
356 oh4->src_address.as_u32 = ih4->src_address.as_u32;
357 oh4->dst_address.as_u32 = ih4->dst_address.as_u32;
359 clib_host_to_net_u16 (vlib_buffer_length_in_chain
361 oh4->checksum = ip4_header_checksum (oh4);
365 /* for IPSec-GRE tunnel next node is ipsec-gre-input */
367 ((vnet_buffer (i_b0)->ipsec.flags) &
368 IPSEC_FLAG_IPSEC_GRE_TUNNEL))
369 next0 = ESP_DECRYPT_NEXT_IPSEC_GRE_INPUT;
371 vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
375 if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
379 o_b0->flags |= VLIB_BUFFER_IS_TRACED;
380 o_b0->trace_index = i_b0->trace_index;
381 esp_decrypt_trace_t *tr =
382 vlib_add_trace (vm, node, o_b0, sizeof (*tr));
383 tr->crypto_alg = sa0->crypto_alg;
384 tr->integ_alg = sa0->integ_alg;
388 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
389 n_left_to_next, o_bi0, next0);
391 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
393 vlib_node_increment_counter (vm, esp_decrypt_node.index,
394 ESP_DECRYPT_ERROR_RX_PKTS,
395 from_frame->n_vectors);
397 free_buffers_and_exit:
399 vlib_buffer_free (vm, recycle, vec_len (recycle));
401 return from_frame->n_vectors;
406 VLIB_REGISTER_NODE (esp_decrypt_node) = {
407 .function = esp_decrypt_node_fn,
408 .name = "esp-decrypt",
409 .vector_size = sizeof (u32),
410 .format_trace = format_esp_decrypt_trace,
411 .type = VLIB_NODE_TYPE_INTERNAL,
413 .n_errors = ARRAY_LEN(esp_decrypt_error_strings),
414 .error_strings = esp_decrypt_error_strings,
416 .n_next_nodes = ESP_DECRYPT_N_NEXT,
418 #define _(s,n) [ESP_DECRYPT_NEXT_##s] = n,
419 foreach_esp_decrypt_next
425 VLIB_NODE_FUNCTION_MULTIARCH (esp_decrypt_node, esp_decrypt_node_fn)
427 * fd.io coding-style-patch-verification: ON
430 * eval: (c-set-style "gnu")