esp_decrypt.c

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/*
 * esp_decrypt.c : IPSec ESP Decrypt node using DPDK Cryptodev
 *
 * Copyright (c) 2017 Intel 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 opy 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>
#include <dpdk/ipsec/ipsec.h>
#include <dpdk/device/dpdk.h>
#include <dpdk/device/dpdk_priv.h>

#define foreach_esp_decrypt_next               \
_(DROP, "error-drop")                          \
_(IP4_INPUT, "ip4-input-no-checksum")          \
_(IP6_INPUT, "ip6-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")                 \
 _(DECRYPTION_FAILED, "ESP decryption failed")   \
 _(REPLAY, "SA replayed packet")                 \
 _(NOT_IP, "Not IP packet (dropped)")            \
 _(ENQ_FAIL, "Enqueue failed (buffer full)")     \
 _(DISCARD, "Not enough crypto operations, discarding frame")  \
 _(BAD_LEN, "Invalid ciphertext length")         \
 _(SESSION, "Failed to get crypto session")      \
 _(NOSUP, "Cipher/Auth not supported")


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 _
};

vlib_node_registration_t dpdk_esp_decrypt_node;

typedef struct {
  ipsec_crypto_alg_t crypto_alg;
  ipsec_integ_alg_t integ_alg;
  u8 packet_data[64];
} 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 *);
  u32 indent = format_get_indent (s);

  s = format (s, "cipher %U auth %U\n",
              format_ipsec_crypto_alg, t->crypto_alg,
              format_ipsec_integ_alg, t->integ_alg);
  s = format (s, "%U%U",
              format_white_space, indent,
              format_esp_header, t->packet_data);
  return s;
}

static uword
dpdk_esp_decrypt_node_fn (vlib_main_t * vm,
             vlib_node_runtime_t * node,
             vlib_frame_t * from_frame)
{
  u32 n_left_from, *from, *to_next, next_index;
  ipsec_main_t *im = &ipsec_main;
  u32 thread_idx = vlib_get_thread_index();
  dpdk_crypto_main_t *dcm = &dpdk_crypto_main;
  crypto_resource_t *res = 0;
  ipsec_sa_t *sa0 = 0;
  crypto_alg_t *cipher_alg = 0, *auth_alg = 0;
  struct rte_cryptodev_sym_session *session = 0;
  u32 ret, last_sa_index = ~0;
  u8 numa = rte_socket_id ();
  u8 is_aead = 0;
  crypto_worker_main_t *cwm =
    vec_elt_at_index (dcm->workers_main, thread_idx);
  struct rte_crypto_op **ops = cwm->ops;

  from = vlib_frame_vector_args (from_frame);
  n_left_from = from_frame->n_vectors;

  ret = crypto_alloc_ops (numa, ops, n_left_from);
  if (ret)
    {
      vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                                   ESP_DECRYPT_ERROR_DISCARD, 1);
      /* Discard whole frame */
      return n_left_from;
    }

  next_index = ESP_DECRYPT_NEXT_DROP;

  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)
        {
          clib_error_t *error;
          u32 bi0, sa_index0, seq, iv_size;
          u8 trunc_size;
          vlib_buffer_t *b0;
          esp_header_t *esp0;
          struct rte_mbuf *mb0;
          struct rte_crypto_op *op;
          u16 res_idx;

          bi0 = from[0];
          from += 1;
          n_left_from -= 1;

          b0 = vlib_get_buffer (vm, bi0);
          mb0 = rte_mbuf_from_vlib_buffer(b0);
          esp0 = vlib_buffer_get_current (b0);

          /* ih0/ih6_0 */
          CLIB_PREFETCH (esp0, sizeof (esp0[0]) + 16, LOAD);
          /* mb0 */
          CLIB_PREFETCH (mb0, CLIB_CACHE_LINE_BYTES, STORE);

          op = ops[0];
          ops += 1;
          ASSERT (op->status == RTE_CRYPTO_OP_STATUS_NOT_PROCESSED);

          dpdk_op_priv_t *priv = crypto_op_get_priv (op);

          u16 op_len =
            sizeof (op[0]) + sizeof (op[0].sym[0]) + sizeof (priv[0]);
          CLIB_PREFETCH (op, op_len, STORE);

          sa_index0 = vnet_buffer(b0)->ipsec.sad_index;

          if (sa_index0 != last_sa_index)
            {
              sa0 = pool_elt_at_index (im->sad, sa_index0);

              cipher_alg = vec_elt_at_index (dcm->cipher_algs, sa0->crypto_alg);
              auth_alg = vec_elt_at_index (dcm->auth_algs, sa0->integ_alg);

              is_aead = (cipher_alg->type == RTE_CRYPTO_SYM_XFORM_AEAD);
              if (is_aead)
                auth_alg = cipher_alg;

              res_idx = get_resource (cwm, sa0);

              if (PREDICT_FALSE (res_idx == (u16) ~0))
                {
                  clib_warning ("unsupported SA by thread index %u", thread_idx);
                  vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                                               ESP_DECRYPT_ERROR_NOSUP, 1);
                  to_next[0] = bi0;
                  to_next += 1;
                  n_left_to_next -= 1;
                  goto trace;
                }
              res = vec_elt_at_index (dcm->resource, res_idx);

              error = crypto_get_session (&session, sa_index0, res, cwm, 0);
              if (PREDICT_FALSE (error || !session))
                {
                  clib_warning ("failed to get crypto session");
                  vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                                               ESP_DECRYPT_ERROR_SESSION, 1);
                  to_next[0] = bi0;
                  to_next += 1;
                  n_left_to_next -= 1;
                  goto trace;
                }

              last_sa_index = sa_index0;
            }

          /* anti-replay check */
          if (sa0->use_anti_replay)
            {
              int rv = 0;

              seq = clib_net_to_host_u32 (esp0->seq);

              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 ("failed anti-replay check");
                  vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                                               ESP_DECRYPT_ERROR_REPLAY, 1);
                  to_next[0] = bi0;
                  to_next += 1;
                  n_left_to_next -= 1;
                  goto trace;
                }
            }

          priv->next = DPDK_CRYPTO_INPUT_NEXT_DECRYPT_POST;

          /* FIXME multi-seg */
          sa0->total_data_size += b0->current_length;

          res->ops[res->n_ops] = op;
          res->bi[res->n_ops] = bi0;
          res->n_ops += 1;

          /* Convert vlib buffer to mbuf */
          mb0->data_len = b0->current_length;
          mb0->pkt_len = b0->current_length;
          mb0->data_off = RTE_PKTMBUF_HEADROOM + b0->current_data;

          trunc_size = auth_alg->trunc_size;
          iv_size = cipher_alg->iv_len;

          /* Outer IP header has already been stripped */
          u16 payload_len =
            b0->current_length - sizeof (esp_header_t) - iv_size - trunc_size;

          ASSERT (payload_len >= 4);

          if (payload_len & (cipher_alg->boundary - 1))
            {
              clib_warning ("payload %u not multiple of %d\n",
                            payload_len, cipher_alg->boundary);
              vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                                           ESP_DECRYPT_ERROR_BAD_LEN, 1);
              res->n_ops -= 1;
              to_next[0] = bi0;
              to_next += 1;
              n_left_to_next -= 1;
              goto trace;
            }

          u32 cipher_off, cipher_len;
          u32 auth_len = 0;
          u8 *aad = NULL;

          u8 *iv = (u8 *) (esp0 + 1);

          dpdk_gcm_cnt_blk *icb = &priv->cb;

          cipher_off = sizeof (esp_header_t) + iv_size;
          cipher_len = payload_len;

          u8 *digest = vlib_buffer_get_tail (b0) - trunc_size;
          u64 digest_paddr =
            mb0->buf_physaddr + digest - ((u8 *) mb0->buf_addr);

          if (!is_aead && cipher_alg->alg == RTE_CRYPTO_CIPHER_AES_CBC)
            clib_memcpy(icb, iv, 16);
          else /* CTR/GCM */
            {
              u32 *_iv = (u32 *) iv;

              crypto_set_icb (icb, sa0->salt, _iv[0], _iv[1]);
            }

          if (is_aead)
            {
              aad = priv->aad;
              u32 * _aad = (u32 *) aad;
              clib_memcpy (aad, esp0, 8);

              /* _aad[3] should always be 0 */
              if (PREDICT_FALSE (sa0->use_esn))
                _aad[2] = clib_host_to_net_u32 (sa0->seq_hi);
              else
                _aad[2] = 0;
            }
          else
            {
              auth_len = sizeof(esp_header_t) + iv_size + payload_len;

              if (sa0->use_esn)
                {
                  clib_memcpy (priv->icv, digest, trunc_size);
                  u32 *_digest = (u32 *) digest;
                  _digest[0] = clib_host_to_net_u32 (sa0->seq_hi);
                  auth_len += sizeof(sa0->seq_hi);

                  digest = priv->icv;
                  digest_paddr =
                    op->phys_addr + (uintptr_t) priv->icv - (uintptr_t) op;
                }
            }

          crypto_op_setup (is_aead, mb0, op, session, cipher_off, cipher_len,
                           0, auth_len, aad, digest, digest_paddr);
trace:
          if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
            {
              esp_decrypt_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
              tr->crypto_alg = sa0->crypto_alg;
              tr->integ_alg = sa0->integ_alg;
              clib_memcpy (tr->packet_data, vlib_buffer_get_current (b0),
                           sizeof (esp_header_t));
            }
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                               ESP_DECRYPT_ERROR_RX_PKTS,
                               from_frame->n_vectors);

  crypto_enqueue_ops (vm, cwm, 0, dpdk_esp_decrypt_node.index,
                      ESP_DECRYPT_ERROR_ENQ_FAIL, numa);

  crypto_free_ops (numa, ops, cwm->ops + from_frame->n_vectors - ops);

  return from_frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (dpdk_esp_decrypt_node) = {
  .function = dpdk_esp_decrypt_node_fn,
  .name = "dpdk-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 (dpdk_esp_decrypt_node, dpdk_esp_decrypt_node_fn)

/*
 * Decrypt Post Node
 */

#define foreach_esp_decrypt_post_error        \
 _(PKTS, "ESP post pkts")

typedef enum {
#define _(sym,str) ESP_DECRYPT_POST_ERROR_##sym,
  foreach_esp_decrypt_post_error
#undef _
  ESP_DECRYPT_POST_N_ERROR,
} esp_decrypt_post_error_t;

static char * esp_decrypt_post_error_strings[] = {
#define _(sym,string) string,
  foreach_esp_decrypt_post_error
#undef _
};

vlib_node_registration_t dpdk_esp_decrypt_post_node;

static u8 * format_esp_decrypt_post_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 *);
  u32 indent = format_get_indent (s);

  s = format (s, "cipher %U auth %U\n",
              format_ipsec_crypto_alg, t->crypto_alg,
              format_ipsec_integ_alg, t->integ_alg);

  ip4_header_t *ih4 = (ip4_header_t *) t->packet_data;
  if ((ih4->ip_version_and_header_length & 0xF0) == 0x60)
    s = format (s, "%U%U", format_white_space, indent, format_ip6_header, ih4);
  else
    s = format (s, "%U%U", format_white_space, indent, format_ip4_header, ih4);

  return s;
}

static uword
dpdk_esp_decrypt_post_node_fn (vlib_main_t * vm,
             vlib_node_runtime_t * node,
             vlib_frame_t * from_frame)
{
  u32 n_left_from, *from, *to_next = 0, next_index;
  ipsec_sa_t * sa0;
  u32 sa_index0 = ~0;
  ipsec_main_t *im = &ipsec_main;
  dpdk_crypto_main_t *dcm = &dpdk_crypto_main;

  from = vlib_frame_vector_args (from_frame);
  n_left_from = from_frame->n_vectors;

  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)
        {
          esp_footer_t * f0;
          u32 bi0, iv_size, next0;
          vlib_buffer_t * b0 = 0;
          ip4_header_t *ih4 = 0, *oh4 = 0;
          ip6_header_t *ih6 = 0, *oh6 = 0;
          crypto_alg_t *cipher_alg, *auth_alg;
          esp_header_t *esp0;
          u8 trunc_size, is_aead;
          u16 udp_encap_adv = 0;

          next0 = ESP_DECRYPT_NEXT_DROP;

          bi0 = from[0];
          from += 1;
          n_left_from -= 1;
          n_left_to_next -= 1;

          b0 = vlib_get_buffer (vm, bi0);
          esp0 = vlib_buffer_get_current (b0);

          sa_index0 = vnet_buffer(b0)->ipsec.sad_index;
          sa0 = pool_elt_at_index (im->sad, sa_index0);

          to_next[0] = bi0;
          to_next += 1;

          cipher_alg = vec_elt_at_index (dcm->cipher_algs, sa0->crypto_alg);
          auth_alg = vec_elt_at_index (dcm->auth_algs, sa0->integ_alg);
          is_aead = cipher_alg->type == RTE_CRYPTO_SYM_XFORM_AEAD;
          if (is_aead)
            auth_alg = cipher_alg;

          trunc_size = auth_alg->trunc_size;

          iv_size = cipher_alg->iv_len;

          if (sa0->use_anti_replay)
            {
              u32 seq;
              seq = clib_host_to_net_u32(esp0->seq);
              if (PREDICT_TRUE(sa0->use_esn))
                esp_replay_advance_esn(sa0, seq);
              else
                esp_replay_advance(sa0, seq);
            }

          /* if UDP encapsulation is used adjust the address of the IP header */
          if (sa0->udp_encap && (b0->flags & VNET_BUFFER_F_IS_IP4))
            {
              udp_encap_adv = sizeof (udp_header_t);
            }

          if (b0->flags & VNET_BUFFER_F_IS_IP4)
            ih4 = (ip4_header_t *)
               ((u8 *) esp0 - udp_encap_adv - sizeof (ip4_header_t));
          else
            ih4 =
               (ip4_header_t *) ((u8 *) esp0 - sizeof (ip6_header_t));

          vlib_buffer_advance (b0, sizeof (esp_header_t) + iv_size);

          b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
          f0 = (esp_footer_t *) (vlib_buffer_get_tail (b0) - trunc_size - 2);
          b0->current_length -= (f0->pad_length + trunc_size + 2);
#if 0
          /* check padding */
          const u8 *padding = vlib_buffer_get_tail (b0);
          if (PREDICT_FALSE (memcmp (padding, pad_data, f0->pad_length)))
            {
              clib_warning("bad padding");
              vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                                           ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
                                           1);
              goto trace;
            }
#endif
          if (sa0->is_tunnel)
            {
              if (f0->next_header == IP_PROTOCOL_IP_IN_IP)
                next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
              else if (sa0->is_tunnel_ip6 && 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, dpdk_esp_decrypt_node.index,
                                               ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
                                               1);
                  goto trace;
                }
            }
          else /* transport mode */
            {
              if ((ih4->ip_version_and_header_length & 0xF0) == 0x40)
                {
                  u16 ih4_len = ip4_header_bytes (ih4);
                  vlib_buffer_advance (b0, - ih4_len - udp_encap_adv);
                  next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
                  if (!sa0->udp_encap)
                    {
                          oh4 = vlib_buffer_get_current (b0);
                          memmove(oh4, ih4, ih4_len);
                          oh4->protocol = f0->next_header;
                          oh4->length = clib_host_to_net_u16 (b0->current_length);
                          oh4->checksum = ip4_header_checksum(oh4);
                    }
                }
              else if ((ih4->ip_version_and_header_length & 0xF0) == 0x60)
                {
                  ih6 = (ip6_header_t *) ih4;
                  vlib_buffer_advance (b0, -sizeof(ip6_header_t));
                  oh6 = vlib_buffer_get_current (b0);
                  memmove(oh6, ih6, sizeof(ip6_header_t));

                  next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
                  oh6->protocol = f0->next_header;
                  u16 len = b0->current_length - sizeof (ip6_header_t);
                  oh6->payload_length = clib_host_to_net_u16 (len);
                }
              else
                {
                  clib_warning("next header: 0x%x", f0->next_header);
                  vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                                               ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
                                               1);
                  goto trace;
                }
            }

          vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32)~0;

        trace:
          if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
            {
              esp_decrypt_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
              tr->crypto_alg = sa0->crypto_alg;
              tr->integ_alg = sa0->integ_alg;
              ih4 = vlib_buffer_get_current (b0);
              clib_memcpy (tr->packet_data, ih4, sizeof (ip6_header_t));
            }

          vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
                                           to_next, n_left_to_next, bi0, next0);
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  vlib_node_increment_counter (vm, dpdk_esp_decrypt_post_node.index,
                               ESP_DECRYPT_POST_ERROR_PKTS,
                               from_frame->n_vectors);

  return from_frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (dpdk_esp_decrypt_post_node) = {
  .function = dpdk_esp_decrypt_post_node_fn,
  .name = "dpdk-esp-decrypt-post",
  .vector_size = sizeof (u32),
  .format_trace = format_esp_decrypt_post_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = ARRAY_LEN(esp_decrypt_post_error_strings),
  .error_strings = esp_decrypt_post_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 (dpdk_esp_decrypt_post_node, dpdk_esp_decrypt_post_node_fn)