esp_decrypt.c

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/*
 * esp_decrypt.c : IPSec ESP Decrypt node using DPDK Cryptodev
 *
 * Copyright (c) 2016 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 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 <dpdk/ipsec/ipsec.h>
#include <dpdk/ipsec/esp.h>
#include <dpdk/device/dpdk.h>
#include <dpdk/device/dpdk_priv.h>

#define foreach_esp_decrypt_next               \
_(DROP, "error-drop")                          \
_(IP4_INPUT, "ip4-input")                      \
_(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)")     \
 _(NO_CRYPTODEV, "Cryptodev not configured")     \
 _(BAD_LEN, "Invalid ciphertext length")


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;
} 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;
}

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_index = vlib_get_thread_index();
  dpdk_crypto_main_t * dcm = &dpdk_crypto_main;
  dpdk_esp_main_t * em = &dpdk_esp_main;
  u32 i;

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

  crypto_worker_main_t *cwm =
    vec_elt_at_index(dcm->workers_main, thread_index);
  u32 n_qps = vec_len(cwm->qp_data);
  struct rte_crypto_op ** cops_to_enq[n_qps];
  u32 n_cop_qp[n_qps], * bi_to_enq[n_qps];

  for (i = 0; i < n_qps; i++)
    {
      bi_to_enq[i] = cwm->qp_data[i].bi;
      cops_to_enq[i] = cwm->qp_data[i].cops;
    }

  memset(n_cop_qp, 0, n_qps * sizeof(u32));

  crypto_alloc_cops();

  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)
        {
          u32 bi0, sa_index0 = ~0, seq, trunc_size, iv_size;
          vlib_buffer_t * b0;
          esp_header_t * esp0;
          ipsec_sa_t * sa0;
          struct rte_mbuf * mb0 = 0;
          const int BLOCK_SIZE = 16;
          crypto_sa_session_t * sa_sess;
          void * sess;
          u16 qp_index;
          struct rte_crypto_op * cop = 0;

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

          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, dpdk_esp_decrypt_node.index,
                                               ESP_DECRYPT_ERROR_REPLAY, 1);
                  to_next[0] = bi0;
                  to_next += 1;
                  n_left_to_next -= 1;
                  goto trace;
                }
            }

          sa0->total_data_size += b0->current_length;

          sa_sess = pool_elt_at_index(cwm->sa_sess_d[0], sa_index0);

          if (PREDICT_FALSE(!sa_sess->sess))
            {
              int ret = create_sym_sess(sa0, sa_sess, 0);

              if (PREDICT_FALSE (ret))
                {
                  to_next[0] = bi0;
                  to_next += 1;
                  n_left_to_next -= 1;
                  goto trace;
                }
            }

          sess = sa_sess->sess;
          qp_index = sa_sess->qp_index;

          ASSERT (vec_len (vec_elt (cwm->qp_data, qp_index).free_cops) > 0);
          cop = vec_pop (vec_elt (cwm->qp_data, qp_index).free_cops);
          ASSERT (cop->status == RTE_CRYPTO_OP_STATUS_NOT_PROCESSED);

          cops_to_enq[qp_index][0] = cop;
          cops_to_enq[qp_index] += 1;
          n_cop_qp[qp_index] += 1;
          bi_to_enq[qp_index][0] = bi0;
          bi_to_enq[qp_index] += 1;

          rte_crypto_op_attach_sym_session(cop, sess);

          if (sa0->crypto_alg == IPSEC_CRYPTO_ALG_AES_GCM_128)
            trunc_size = 16;
          else
            trunc_size = em->esp_integ_algs[sa0->integ_alg].trunc_size;
          iv_size = em->esp_crypto_algs[sa0->crypto_alg].iv_len;

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

          /* Outer IP header has already been stripped */
          u16 payload_len = rte_pktmbuf_pkt_len(mb0) - sizeof (esp_header_t) -
              iv_size - trunc_size;

          if ((payload_len & (BLOCK_SIZE - 1)) || (payload_len <= 0))
            {
              clib_warning ("payload %u not multiple of %d\n",
                            payload_len, BLOCK_SIZE);
              vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                                           ESP_DECRYPT_ERROR_BAD_LEN, 1);
              vec_add (vec_elt (cwm->qp_data, qp_index).free_cops, &cop, 1);
              bi_to_enq[qp_index] -= 1;
              cops_to_enq[qp_index] -= 1;
              n_cop_qp[qp_index] -= 1;
              to_next[0] = bi0;
              to_next += 1;
              n_left_to_next -= 1;
              goto trace;
            }

          struct rte_crypto_sym_op *sym_cop = (struct rte_crypto_sym_op *)(cop + 1);

          u8 is_aead = sa0->crypto_alg == IPSEC_CRYPTO_ALG_AES_GCM_128;
          u32 cipher_off, cipher_len;
          u32 auth_off = 0, auth_len = 0, aad_size = 0;
          u8 *aad = NULL, *digest = NULL;
          u64 digest_paddr;

          u8 *iv = rte_pktmbuf_mtod_offset(mb0, void*, sizeof (esp_header_t));
          dpdk_cop_priv_t *priv = (dpdk_cop_priv_t *)(sym_cop + 1);
          dpdk_gcm_cnt_blk *icb = &priv->cb;

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

          digest =
            vlib_buffer_get_current (b0) + sizeof(esp_header_t) +
            iv_size + payload_len;

          digest_paddr = mb0->buf_physaddr + (digest - (u8 *) mb0->buf_addr);

          if (is_aead)
            {
              u32 *_iv = (u32 *) iv;

              crypto_set_icb (icb, sa0->salt, _iv[0], _iv[1]);
              iv_size = 16;

              aad = priv->aad;
              clib_memcpy(aad, esp0, 8);
              aad_size = 8;
              if (sa0->use_esn)
                {
                  *((u32*)&aad[8]) = sa0->seq_hi;
                  aad_size = 12;
                }
            }
          else
            {
              clib_memcpy(icb, iv, 16);

              auth_off = 0;
              auth_len = sizeof(esp_header_t) + iv_size + payload_len;

              if (sa0->use_esn)
                {
                  dpdk_cop_priv_t* priv = (dpdk_cop_priv_t*) (sym_cop + 1);

                  clib_memcpy (priv->icv, digest, trunc_size);
                  *((u32*) digest) = sa0->seq_hi;
                  auth_len += sizeof(sa0->seq_hi);

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

          crypto_op_setup (is_aead, mb0, cop, sess,
                           cipher_off, cipher_len, (u8 *) icb, iv_size,
                           auth_off, auth_len, aad, aad_size,
                           digest, digest_paddr, trunc_size);
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;
            }
        }
      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_qp_data_t *qpd;
  /* *INDENT-OFF* */
  vec_foreach_index (i, cwm->qp_data)
    {
      u32 enq;

      if (!n_cop_qp[i])
        continue;

      qpd = vec_elt_at_index(cwm->qp_data, i);
      enq = rte_cryptodev_enqueue_burst(qpd->dev_id, qpd->qp_id,
                                        qpd->cops, n_cop_qp[i]);
      qpd->inflights += enq;

      if (PREDICT_FALSE(enq < n_cop_qp[i]))
        {
          crypto_free_cop (qpd, &qpd->cops[enq], n_cop_qp[i] - enq);
          vlib_buffer_free (vm, &qpd->bi[enq], n_cop_qp[i] - enq);

          vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                                       ESP_DECRYPT_ERROR_ENQ_FAIL,
                                       n_cop_qp[i] - enq);
        }
    }
  /* *INDENT-ON* */

  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)
{
  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_esp_main_t *em = &dpdk_esp_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, next0, trunc_size, iv_size;
          vlib_buffer_t * b0 = 0;
          ip4_header_t *ih4 = 0, *oh4 = 0;
          ip6_header_t *ih6 = 0, *oh6 = 0;
          u8 tunnel_mode = 1;
          u8 transport_ip6 = 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);

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

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

          if (sa0->crypto_alg == IPSEC_CRYPTO_ALG_AES_GCM_128)
            trunc_size = 16;
          else
            trunc_size = em->esp_integ_algs[sa0->integ_alg].trunc_size;
          iv_size = em->esp_crypto_algs[sa0->crypto_alg].iv_len;

          if (sa0->use_anti_replay)
            {
              esp_header_t * esp0 = vlib_buffer_get_current (b0);
              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);
            }

          ih4 = (ip4_header_t *) (b0->data + sizeof(ethernet_header_t));
          vlib_buffer_advance (b0, sizeof (esp_header_t) + iv_size);

          b0->current_length -= (trunc_size + 2);
          b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
          f0 = (esp_footer_t *) ((u8 *) vlib_buffer_get_current (b0) +
                                 b0->current_length);
          b0->current_length -= f0->pad_length;

          /* transport mode */
          if (PREDICT_FALSE(!sa0->is_tunnel && !sa0->is_tunnel_ip6))
            {
              tunnel_mode = 0;

              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;
                  else
                    {
                      clib_warning("next header: 0x%x", f0->next_header);
                      vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
                                                   ESP_DECRYPT_ERROR_NOT_IP, 1);
                      goto trace;
                    }
                }
            }

          if (PREDICT_TRUE (tunnel_mode))
            {
              if (PREDICT_TRUE(f0->next_header == IP_PROTOCOL_IP_IN_IP))
                next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
              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, dpdk_esp_decrypt_node.index,
                                               ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
                                               1);
                  goto trace;
                }
            }
          /* transport mode */
          else
            {
              if (PREDICT_FALSE(transport_ip6))
                {
                  ih6 = (ip6_header_t *) (b0->data + sizeof(ethernet_header_t));
                  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;
                  oh6->payload_length =
                      clib_host_to_net_u16 (
                          vlib_buffer_length_in_chain(vm, b0) -
                          sizeof (ip6_header_t));
                }
              else
                {
                  vlib_buffer_advance (b0, -sizeof(ip4_header_t));
                  oh4 = vlib_buffer_get_current (b0);
                  memmove(oh4, ih4, sizeof(ip4_header_t));

                  next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
                  oh4->ip_version_and_header_length = 0x45;
                  oh4->fragment_id = 0;
                  oh4->flags_and_fragment_offset = 0;
                  oh4->protocol = f0->next_header;
                  oh4->length = clib_host_to_net_u16 (
                      vlib_buffer_length_in_chain (vm, b0));
                  oh4->checksum = ip4_header_checksum (oh4);
                }
            }

          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;
            }

          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)