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-rw-r--r--src/vnet/ipsec/esp_decrypt.c430
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:
+ */