2 * esp_encrypt.c : IPSec ESP encrypt 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 ESP_SEQ_MAX (4294967295UL)
27 #define foreach_esp_encrypt_next \
28 _(DROP, "error-drop") \
29 _(IP4_INPUT, "ip4-input") \
30 _(IP6_INPUT, "ip6-input") \
31 _(INTERFACE_OUTPUT, "interface-output")
33 #define _(v, s) ESP_ENCRYPT_NEXT_##v,
36 foreach_esp_encrypt_next
41 #define foreach_esp_encrypt_error \
42 _(RX_PKTS, "ESP pkts received") \
43 _(NO_BUFFER, "No buffer (packet dropped)") \
44 _(DECRYPTION_FAILED, "ESP encryption failed") \
45 _(SEQ_CYCLED, "sequence number cycled")
50 #define _(sym,str) ESP_ENCRYPT_ERROR_##sym,
51 foreach_esp_encrypt_error
54 } esp_encrypt_error_t;
56 static char *esp_encrypt_error_strings[] = {
57 #define _(sym,string) string,
58 foreach_esp_encrypt_error
62 vlib_node_registration_t esp_encrypt_node;
68 ipsec_crypto_alg_t crypto_alg;
69 ipsec_integ_alg_t integ_alg;
70 } esp_encrypt_trace_t;
72 /* packet trace format function */
74 format_esp_encrypt_trace (u8 * s, va_list * args)
76 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
77 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
78 esp_encrypt_trace_t *t = va_arg (*args, esp_encrypt_trace_t *);
80 s = format (s, "esp: spi %u seq %u crypto %U integrity %U",
82 format_ipsec_crypto_alg, t->crypto_alg,
83 format_ipsec_integ_alg, t->integ_alg);
88 esp_encrypt_aes_cbc (ipsec_crypto_alg_t alg,
89 u8 * in, u8 * out, size_t in_len, u8 * key, u8 * iv)
91 esp_main_t *em = &esp_main;
92 u32 cpu_index = os_get_cpu_number ();
93 EVP_CIPHER_CTX *ctx = &(em->per_thread_data[cpu_index].encrypt_ctx);
94 const EVP_CIPHER *cipher = NULL;
97 ASSERT (alg < IPSEC_CRYPTO_N_ALG);
99 if (PREDICT_FALSE (em->esp_crypto_algs[alg].type == IPSEC_CRYPTO_ALG_NONE))
102 if (PREDICT_FALSE (alg != em->per_thread_data[cpu_index].last_encrypt_alg))
104 cipher = em->esp_crypto_algs[alg].type;
105 em->per_thread_data[cpu_index].last_encrypt_alg = alg;
108 EVP_EncryptInit_ex (ctx, cipher, NULL, key, iv);
110 EVP_EncryptUpdate (ctx, out, &out_len, in, in_len);
111 EVP_EncryptFinal_ex (ctx, out + out_len, &out_len);
115 esp_seq_advance (ipsec_sa_t * sa)
117 if (PREDICT_TRUE (sa->use_esn))
119 if (PREDICT_FALSE (sa->seq == ESP_SEQ_MAX))
122 (sa->use_anti_replay && sa->seq_hi == ESP_SEQ_MAX))
130 if (PREDICT_FALSE (sa->use_anti_replay && sa->seq == ESP_SEQ_MAX))
139 esp_encrypt_node_fn (vlib_main_t * vm,
140 vlib_node_runtime_t * node, vlib_frame_t * from_frame)
142 u32 n_left_from, *from, *to_next = 0, next_index;
143 from = vlib_frame_vector_args (from_frame);
144 n_left_from = from_frame->n_vectors;
145 ipsec_main_t *im = &ipsec_main;
147 u32 cpu_index = os_get_cpu_number ();
149 ipsec_alloc_empty_buffers (vm, im);
151 u32 *empty_buffers = im->empty_buffers[cpu_index];
153 if (PREDICT_FALSE (vec_len (empty_buffers) < n_left_from))
155 vlib_node_increment_counter (vm, esp_encrypt_node.index,
156 ESP_ENCRYPT_ERROR_NO_BUFFER, n_left_from);
157 clib_warning ("no enough empty buffers. discarding frame");
158 goto free_buffers_and_exit;
161 next_index = node->cached_next_index;
163 while (n_left_from > 0)
167 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
169 while (n_left_from > 0 && n_left_to_next > 0)
171 u32 i_bi0, o_bi0, next0;
172 vlib_buffer_t *i_b0, *o_b0 = 0;
175 ip4_and_esp_header_t *ih0, *oh0 = 0;
176 ip6_and_esp_header_t *ih6_0, *oh6_0 = 0;
177 uword last_empty_buffer;
178 esp_header_t *o_esp0;
184 u8 transport_mode = 0;
191 next0 = ESP_ENCRYPT_NEXT_DROP;
193 i_b0 = vlib_get_buffer (vm, i_bi0);
194 sa_index0 = vnet_buffer (i_b0)->output_features.ipsec_sad_index;
195 sa0 = pool_elt_at_index (im->sad, sa_index0);
197 if (PREDICT_FALSE (esp_seq_advance (sa0)))
199 clib_warning ("sequence number counter has cycled SPI %u",
201 vlib_node_increment_counter (vm, esp_encrypt_node.index,
202 ESP_ENCRYPT_ERROR_SEQ_CYCLED, 1);
208 /* grab free buffer */
209 last_empty_buffer = vec_len (empty_buffers) - 1;
210 o_bi0 = empty_buffers[last_empty_buffer];
211 o_b0 = vlib_get_buffer (vm, o_bi0);
212 o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
213 o_b0->current_data = sizeof (ethernet_header_t);
214 ih0 = vlib_buffer_get_current (i_b0);
215 vlib_prefetch_buffer_with_index (vm,
216 empty_buffers[last_empty_buffer -
218 _vec_len (empty_buffers) = last_empty_buffer;
222 /* add old buffer to the recycle list */
223 vec_add1 (recycle, i_bi0);
227 ((ih0->ip4.ip_version_and_header_length & 0xF0) == 0x60))
230 ih6_0 = vlib_buffer_get_current (i_b0);
231 ip_hdr_size = sizeof (ip6_header_t);
232 next_hdr_type = IP_PROTOCOL_IPV6;
233 oh6_0 = vlib_buffer_get_current (o_b0);
234 o_esp0 = vlib_buffer_get_current (o_b0) + sizeof (ip6_header_t);
236 oh6_0->ip6.ip_version_traffic_class_and_flow_label =
237 ih6_0->ip6.ip_version_traffic_class_and_flow_label;
238 oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_ESP;
239 oh6_0->ip6.hop_limit = 254;
240 oh6_0->ip6.src_address.as_u64[0] =
241 ih6_0->ip6.src_address.as_u64[0];
242 oh6_0->ip6.src_address.as_u64[1] =
243 ih6_0->ip6.src_address.as_u64[1];
244 oh6_0->ip6.dst_address.as_u64[0] =
245 ih6_0->ip6.dst_address.as_u64[0];
246 oh6_0->ip6.dst_address.as_u64[1] =
247 ih6_0->ip6.dst_address.as_u64[1];
248 oh6_0->esp.spi = clib_net_to_host_u32 (sa0->spi);
249 oh6_0->esp.seq = clib_net_to_host_u32 (sa0->seq);
250 ip_proto = ih6_0->ip6.protocol;
255 ip_hdr_size = sizeof (ip4_header_t);
256 next_hdr_type = IP_PROTOCOL_IP_IN_IP;
257 oh0 = vlib_buffer_get_current (o_b0);
258 o_esp0 = vlib_buffer_get_current (o_b0) + sizeof (ip4_header_t);
260 oh0->ip4.ip_version_and_header_length = 0x45;
261 oh0->ip4.tos = ih0->ip4.tos;
262 oh0->ip4.fragment_id = 0;
263 oh0->ip4.flags_and_fragment_offset = 0;
265 oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
266 oh0->ip4.src_address.as_u32 = ih0->ip4.src_address.as_u32;
267 oh0->ip4.dst_address.as_u32 = ih0->ip4.dst_address.as_u32;
268 oh0->esp.spi = clib_net_to_host_u32 (sa0->spi);
269 oh0->esp.seq = clib_net_to_host_u32 (sa0->seq);
270 ip_proto = ih0->ip4.protocol;
273 if (PREDICT_TRUE (sa0->is_tunnel && !sa0->is_tunnel_ip6))
275 oh0->ip4.src_address.as_u32 = sa0->tunnel_src_addr.ip4.as_u32;
276 oh0->ip4.dst_address.as_u32 = sa0->tunnel_dst_addr.ip4.as_u32;
278 /* in tunnel mode send it back to FIB */
279 next0 = ESP_ENCRYPT_NEXT_IP4_INPUT;
280 vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
282 else if (sa0->is_tunnel && sa0->is_tunnel_ip6)
284 oh6_0->ip6.src_address.as_u64[0] =
285 sa0->tunnel_src_addr.ip6.as_u64[0];
286 oh6_0->ip6.src_address.as_u64[1] =
287 sa0->tunnel_src_addr.ip6.as_u64[1];
288 oh6_0->ip6.dst_address.as_u64[0] =
289 sa0->tunnel_dst_addr.ip6.as_u64[0];
290 oh6_0->ip6.dst_address.as_u64[1] =
291 sa0->tunnel_dst_addr.ip6.as_u64[1];
293 /* in tunnel mode send it back to FIB */
294 next0 = ESP_ENCRYPT_NEXT_IP6_INPUT;
295 vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
300 ethernet_header_t *ieh0, *oeh0;
301 ieh0 = (ethernet_header_t *) i_b0->data;
302 oeh0 = (ethernet_header_t *) o_b0->data;
303 clib_memcpy (oeh0, ieh0, sizeof (ethernet_header_t));
304 vlib_buffer_advance (i_b0, ip_hdr_size);
305 next_hdr_type = ip_proto;
306 next0 = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
307 o_b0->flags |= BUFFER_OUTPUT_FEAT_DONE;
308 vnet_buffer (o_b0)->sw_if_index[VLIB_TX] =
309 vnet_buffer (i_b0)->sw_if_index[VLIB_TX];
310 vnet_buffer (o_b0)->output_features.bitmap =
311 vnet_buffer (i_b0)->output_features.bitmap;
314 ASSERT (sa0->crypto_alg < IPSEC_CRYPTO_N_ALG);
316 if (PREDICT_TRUE (sa0->crypto_alg != IPSEC_CRYPTO_ALG_NONE))
319 const int BLOCK_SIZE = 16;
320 const int IV_SIZE = 16;
321 int blocks = 1 + (i_b0->current_length + 1) / BLOCK_SIZE;
323 /* pad packet in input buffer */
324 u8 pad_bytes = BLOCK_SIZE * blocks - 2 - i_b0->current_length;
327 vlib_buffer_get_current (i_b0) + i_b0->current_length;
328 i_b0->current_length = BLOCK_SIZE * blocks;
329 for (i = 0; i < pad_bytes; ++i)
333 f0 = vlib_buffer_get_current (i_b0) + i_b0->current_length - 2;
334 f0->pad_length = pad_bytes;
335 f0->next_header = next_hdr_type;
337 o_b0->current_length = ip_hdr_size + sizeof (esp_header_t) +
338 BLOCK_SIZE * blocks + IV_SIZE;
340 vnet_buffer (o_b0)->sw_if_index[VLIB_RX] =
341 vnet_buffer (i_b0)->sw_if_index[VLIB_RX];
344 RAND_bytes (iv, sizeof (iv));
346 clib_memcpy ((u8 *) vlib_buffer_get_current (o_b0) +
347 ip_hdr_size + sizeof (esp_header_t), iv, 16);
349 esp_encrypt_aes_cbc (sa0->crypto_alg,
350 (u8 *) vlib_buffer_get_current (i_b0),
351 (u8 *) vlib_buffer_get_current (o_b0) +
352 ip_hdr_size + sizeof (esp_header_t) +
353 IV_SIZE, BLOCK_SIZE * blocks,
354 sa0->crypto_key, iv);
357 o_b0->current_length += hmac_calc (sa0->integ_alg, sa0->integ_key,
360 o_b0->current_length -
362 vlib_buffer_get_current (o_b0) +
363 o_b0->current_length,
364 sa0->use_esn, sa0->seq_hi);
367 if (PREDICT_FALSE (is_ipv6))
369 oh6_0->ip6.payload_length =
370 clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0) -
371 sizeof (ip6_header_t));
376 clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0));
377 oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
381 vlib_buffer_reset (o_b0);
384 if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
388 o_b0->flags |= VLIB_BUFFER_IS_TRACED;
389 o_b0->trace_index = i_b0->trace_index;
391 esp_encrypt_trace_t *tr =
392 vlib_add_trace (vm, node, o_b0, sizeof (*tr));
394 tr->seq = sa0->seq - 1;
395 tr->crypto_alg = sa0->crypto_alg;
396 tr->integ_alg = sa0->integ_alg;
399 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
400 to_next, n_left_to_next, o_bi0,
403 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
405 vlib_node_increment_counter (vm, esp_encrypt_node.index,
406 ESP_ENCRYPT_ERROR_RX_PKTS,
407 from_frame->n_vectors);
409 free_buffers_and_exit:
410 vlib_buffer_free (vm, recycle, vec_len (recycle));
412 return from_frame->n_vectors;
417 VLIB_REGISTER_NODE (esp_encrypt_node) = {
418 .function = esp_encrypt_node_fn,
419 .name = "esp-encrypt",
420 .vector_size = sizeof (u32),
421 .format_trace = format_esp_encrypt_trace,
422 .type = VLIB_NODE_TYPE_INTERNAL,
424 .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
425 .error_strings = esp_encrypt_error_strings,
427 .n_next_nodes = ESP_ENCRYPT_N_NEXT,
429 #define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
430 foreach_esp_encrypt_next
436 VLIB_NODE_FUNCTION_MULTIARCH (esp_encrypt_node, esp_encrypt_node_fn)
438 * fd.io coding-style-patch-verification: ON
441 * eval: (c-set-style "gnu")