diff options
Diffstat (limited to 'src/vnet/ipsec/esp_decrypt.c')
| -rw-r--r-- | src/vnet/ipsec/esp_decrypt.c | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/src/vnet/ipsec/esp_decrypt.c b/src/vnet/ipsec/esp_decrypt.c new file mode 100644 index 00000000000..e69cd85101a --- /dev/null +++ b/src/vnet/ipsec/esp_decrypt.c @@ -0,0 +1,430 @@ +/* + * esp_decrypt.c : IPSec ESP decrypt node + * + * Copyright (c) 2015 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <vnet/vnet.h> +#include <vnet/api_errno.h> +#include <vnet/ip/ip.h> + +#include <vnet/ipsec/ipsec.h> +#include <vnet/ipsec/esp.h> + +#define foreach_esp_decrypt_next \ +_(DROP, "error-drop") \ +_(IP4_INPUT, "ip4-input") \ +_(IP6_INPUT, "ip6-input") \ +_(IPSEC_GRE_INPUT, "ipsec-gre-input") + +#define _(v, s) ESP_DECRYPT_NEXT_##v, +typedef enum +{ + foreach_esp_decrypt_next +#undef _ + ESP_DECRYPT_N_NEXT, +} esp_decrypt_next_t; + + +#define foreach_esp_decrypt_error \ + _(RX_PKTS, "ESP pkts received") \ + _(NO_BUFFER, "No buffer (packed dropped)") \ + _(DECRYPTION_FAILED, "ESP decryption failed") \ + _(INTEG_ERROR, "Integrity check failed") \ + _(REPLAY, "SA replayed packet") \ + _(NOT_IP, "Not IP packet (dropped)") + + +typedef enum +{ +#define _(sym,str) ESP_DECRYPT_ERROR_##sym, + foreach_esp_decrypt_error +#undef _ + ESP_DECRYPT_N_ERROR, +} esp_decrypt_error_t; + +static char *esp_decrypt_error_strings[] = { +#define _(sym,string) string, + foreach_esp_decrypt_error +#undef _ +}; + +typedef struct +{ + ipsec_crypto_alg_t crypto_alg; + ipsec_integ_alg_t integ_alg; +} esp_decrypt_trace_t; + +/* packet trace format function */ +static u8 * +format_esp_decrypt_trace (u8 * s, va_list * args) +{ + CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); + CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); + esp_decrypt_trace_t *t = va_arg (*args, esp_decrypt_trace_t *); + + s = format (s, "esp: crypto %U integrity %U", + format_ipsec_crypto_alg, t->crypto_alg, + format_ipsec_integ_alg, t->integ_alg); + return s; +} + +always_inline void +esp_decrypt_aes_cbc (ipsec_crypto_alg_t alg, + u8 * in, u8 * out, size_t in_len, u8 * key, u8 * iv) +{ + esp_main_t *em = &esp_main; + u32 cpu_index = os_get_cpu_number (); + EVP_CIPHER_CTX *ctx = &(em->per_thread_data[cpu_index].decrypt_ctx); + const EVP_CIPHER *cipher = NULL; + int out_len; + + ASSERT (alg < IPSEC_CRYPTO_N_ALG); + + if (PREDICT_FALSE (em->esp_crypto_algs[alg].type == 0)) + return; + + if (PREDICT_FALSE (alg != em->per_thread_data[cpu_index].last_decrypt_alg)) + { + cipher = em->esp_crypto_algs[alg].type; + em->per_thread_data[cpu_index].last_decrypt_alg = alg; + } + + EVP_DecryptInit_ex (ctx, cipher, NULL, key, iv); + + EVP_DecryptUpdate (ctx, out, &out_len, in, in_len); + EVP_DecryptFinal_ex (ctx, out + out_len, &out_len); +} + +static uword +esp_decrypt_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * from_frame) +{ + u32 n_left_from, *from, next_index, *to_next; + ipsec_main_t *im = &ipsec_main; + esp_main_t *em = &esp_main; + u32 *recycle = 0; + from = vlib_frame_vector_args (from_frame); + n_left_from = from_frame->n_vectors; + u32 cpu_index = os_get_cpu_number (); + + ipsec_alloc_empty_buffers (vm, im); + + u32 *empty_buffers = im->empty_buffers[cpu_index]; + + if (PREDICT_FALSE (vec_len (empty_buffers) < n_left_from)) + { + vlib_node_increment_counter (vm, esp_decrypt_node.index, + ESP_DECRYPT_ERROR_NO_BUFFER, n_left_from); + goto free_buffers_and_exit; + } + + next_index = node->cached_next_index; + + while (n_left_from > 0) + { + u32 n_left_to_next; + + vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); + + while (n_left_from > 0 && n_left_to_next > 0) + { + u32 i_bi0, o_bi0 = (u32) ~ 0, next0; + vlib_buffer_t *i_b0; + vlib_buffer_t *o_b0 = 0; + esp_header_t *esp0; + ipsec_sa_t *sa0; + u32 sa_index0 = ~0; + u32 seq; + ip4_header_t *ih4 = 0, *oh4 = 0; + ip6_header_t *ih6 = 0, *oh6 = 0; + u8 tunnel_mode = 1; + u8 transport_ip6 = 0; + + + i_bi0 = from[0]; + from += 1; + n_left_from -= 1; + n_left_to_next -= 1; + + next0 = ESP_DECRYPT_NEXT_DROP; + + i_b0 = vlib_get_buffer (vm, i_bi0); + esp0 = vlib_buffer_get_current (i_b0); + + sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index; + sa0 = pool_elt_at_index (im->sad, sa_index0); + + seq = clib_host_to_net_u32 (esp0->seq); + + /* anti-replay check */ + if (sa0->use_anti_replay) + { + int rv = 0; + + if (PREDICT_TRUE (sa0->use_esn)) + rv = esp_replay_check_esn (sa0, seq); + else + rv = esp_replay_check (sa0, seq); + + if (PREDICT_FALSE (rv)) + { + clib_warning ("anti-replay SPI %u seq %u", sa0->spi, seq); + vlib_node_increment_counter (vm, esp_decrypt_node.index, + ESP_DECRYPT_ERROR_REPLAY, 1); + o_bi0 = i_bi0; + to_next[0] = o_bi0; + to_next += 1; + goto trace; + } + } + + if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE)) + { + u8 sig[64]; + int icv_size = em->esp_integ_algs[sa0->integ_alg].trunc_size; + memset (sig, 0, sizeof (sig)); + u8 *icv = + vlib_buffer_get_current (i_b0) + i_b0->current_length - + icv_size; + i_b0->current_length -= icv_size; + + hmac_calc (sa0->integ_alg, sa0->integ_key, sa0->integ_key_len, + (u8 *) esp0, i_b0->current_length, sig, sa0->use_esn, + sa0->seq_hi); + + if (PREDICT_FALSE (memcmp (icv, sig, icv_size))) + { + vlib_node_increment_counter (vm, esp_decrypt_node.index, + ESP_DECRYPT_ERROR_INTEG_ERROR, + 1); + o_bi0 = i_bi0; + to_next[0] = o_bi0; + to_next += 1; + goto trace; + } + } + + if (PREDICT_TRUE (sa0->use_anti_replay)) + { + if (PREDICT_TRUE (sa0->use_esn)) + esp_replay_advance_esn (sa0, seq); + else + esp_replay_advance (sa0, seq); + } + + /* grab free buffer */ + uword last_empty_buffer = vec_len (empty_buffers) - 1; + o_bi0 = empty_buffers[last_empty_buffer]; + to_next[0] = o_bi0; + to_next += 1; + o_b0 = vlib_get_buffer (vm, o_bi0); + vlib_prefetch_buffer_with_index (vm, + empty_buffers[last_empty_buffer - + 1], STORE); + _vec_len (empty_buffers) = last_empty_buffer; + + /* add old buffer to the recycle list */ + vec_add1 (recycle, i_bi0); + + if (sa0->crypto_alg >= IPSEC_CRYPTO_ALG_AES_CBC_128 && + sa0->crypto_alg <= IPSEC_CRYPTO_ALG_AES_CBC_256) + { + const int BLOCK_SIZE = 16; + const int IV_SIZE = 16; + esp_footer_t *f0; + u8 ip_hdr_size = 0; + + int blocks = + (i_b0->current_length - sizeof (esp_header_t) - + IV_SIZE) / BLOCK_SIZE; + + o_b0->current_data = sizeof (ethernet_header_t); + + /* transport mode */ + if (PREDICT_FALSE (!sa0->is_tunnel && !sa0->is_tunnel_ip6)) + { + tunnel_mode = 0; + ih4 = + (ip4_header_t *) (i_b0->data + + sizeof (ethernet_header_t)); + if (PREDICT_TRUE + ((ih4->ip_version_and_header_length & 0xF0) != 0x40)) + { + if (PREDICT_TRUE + ((ih4->ip_version_and_header_length & 0xF0) == + 0x60)) + { + transport_ip6 = 1; + ip_hdr_size = sizeof (ip6_header_t); + ih6 = + (ip6_header_t *) (i_b0->data + + sizeof (ethernet_header_t)); + oh6 = vlib_buffer_get_current (o_b0); + } + else + { + vlib_node_increment_counter (vm, + esp_decrypt_node.index, + ESP_DECRYPT_ERROR_NOT_IP, + 1); + o_b0 = 0; + goto trace; + } + } + else + { + oh4 = vlib_buffer_get_current (o_b0); + ip_hdr_size = sizeof (ip4_header_t); + } + } + + esp_decrypt_aes_cbc (sa0->crypto_alg, + esp0->data + IV_SIZE, + (u8 *) vlib_buffer_get_current (o_b0) + + ip_hdr_size, BLOCK_SIZE * blocks, + sa0->crypto_key, esp0->data); + + o_b0->current_length = (blocks * 16) - 2 + ip_hdr_size; + o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID; + f0 = + (esp_footer_t *) ((u8 *) vlib_buffer_get_current (o_b0) + + o_b0->current_length); + o_b0->current_length -= f0->pad_length; + + /* tunnel mode */ + if (PREDICT_TRUE (tunnel_mode)) + { + if (PREDICT_TRUE (f0->next_header == IP_PROTOCOL_IP_IN_IP)) + { + next0 = ESP_DECRYPT_NEXT_IP4_INPUT; + oh4 = vlib_buffer_get_current (o_b0); + } + else if (f0->next_header == IP_PROTOCOL_IPV6) + next0 = ESP_DECRYPT_NEXT_IP6_INPUT; + else + { + clib_warning ("next header: 0x%x", f0->next_header); + vlib_node_increment_counter (vm, esp_decrypt_node.index, + ESP_DECRYPT_ERROR_DECRYPTION_FAILED, + 1); + o_b0 = 0; + goto trace; + } + } + /* transport mode */ + else + { + if (PREDICT_FALSE (transport_ip6)) + { + next0 = ESP_DECRYPT_NEXT_IP6_INPUT; + oh6->ip_version_traffic_class_and_flow_label = + ih6->ip_version_traffic_class_and_flow_label; + oh6->protocol = f0->next_header; + oh6->hop_limit = ih6->hop_limit; + oh6->src_address.as_u64[0] = ih6->src_address.as_u64[0]; + oh6->src_address.as_u64[1] = ih6->src_address.as_u64[1]; + oh6->dst_address.as_u64[0] = ih6->dst_address.as_u64[0]; + oh6->dst_address.as_u64[1] = ih6->dst_address.as_u64[1]; + oh6->payload_length = + clib_host_to_net_u16 (vlib_buffer_length_in_chain + (vm, + o_b0) - sizeof (ip6_header_t)); + } + else + { + next0 = ESP_DECRYPT_NEXT_IP4_INPUT; + oh4->ip_version_and_header_length = 0x45; + oh4->tos = ih4->tos; + oh4->fragment_id = 0; + oh4->flags_and_fragment_offset = 0; + oh4->ttl = ih4->ttl; + oh4->protocol = f0->next_header; + oh4->src_address.as_u32 = ih4->src_address.as_u32; + oh4->dst_address.as_u32 = ih4->dst_address.as_u32; + oh4->length = + clib_host_to_net_u16 (vlib_buffer_length_in_chain + (vm, o_b0)); + oh4->checksum = ip4_header_checksum (oh4); + } + } + + /* for IPSec-GRE tunnel next node is ipsec-gre-input */ + if (PREDICT_FALSE + ((vnet_buffer (i_b0)->ipsec.flags) & + IPSEC_FLAG_IPSEC_GRE_TUNNEL)) + next0 = ESP_DECRYPT_NEXT_IPSEC_GRE_INPUT; + + vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; + } + + trace: + if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED)) + { + if (o_b0) + { + o_b0->flags |= VLIB_BUFFER_IS_TRACED; + o_b0->trace_index = i_b0->trace_index; + esp_decrypt_trace_t *tr = + vlib_add_trace (vm, node, o_b0, sizeof (*tr)); + tr->crypto_alg = sa0->crypto_alg; + tr->integ_alg = sa0->integ_alg; + } + } + + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, + n_left_to_next, o_bi0, next0); + } + vlib_put_next_frame (vm, node, next_index, n_left_to_next); + } + vlib_node_increment_counter (vm, esp_decrypt_node.index, + ESP_DECRYPT_ERROR_RX_PKTS, + from_frame->n_vectors); + +free_buffers_and_exit: + if (recycle) + vlib_buffer_free (vm, recycle, vec_len (recycle)); + vec_free (recycle); + return from_frame->n_vectors; +} + + +/* *INDENT-OFF* */ +VLIB_REGISTER_NODE (esp_decrypt_node) = { + .function = esp_decrypt_node_fn, + .name = "esp-decrypt", + .vector_size = sizeof (u32), + .format_trace = format_esp_decrypt_trace, + .type = VLIB_NODE_TYPE_INTERNAL, + + .n_errors = ARRAY_LEN(esp_decrypt_error_strings), + .error_strings = esp_decrypt_error_strings, + + .n_next_nodes = ESP_DECRYPT_N_NEXT, + .next_nodes = { +#define _(s,n) [ESP_DECRYPT_NEXT_##s] = n, + foreach_esp_decrypt_next +#undef _ + }, +}; +/* *INDENT-ON* */ + +VLIB_NODE_FUNCTION_MULTIARCH (esp_decrypt_node, esp_decrypt_node_fn) +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |