esp_encrypt.c

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/*
 * esp_encrypt.c : IPSec ESP encrypt 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 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>
#include <vnet/udp/udp.h>
#include <dpdk/ipsec/ipsec.h>
#include <dpdk/device/dpdk.h>
#include <dpdk/device/dpdk_priv.h>

#define foreach_esp_encrypt_next                   \
_(DROP, "error-drop")                              \
_(IP4_LOOKUP, "ip4-lookup")                        \
_(IP6_LOOKUP, "ip6-lookup")                        \
_(INTERFACE_OUTPUT, "interface-output")

#define _(v, s) ESP_ENCRYPT_NEXT_##v,
typedef enum
{
  foreach_esp_encrypt_next
#undef _
    ESP_ENCRYPT_N_NEXT,
} esp_encrypt_next_t;

#define foreach_esp_encrypt_error                   \
 _(RX_PKTS, "ESP pkts received")                    \
 _(SEQ_CYCLED, "Sequence number cycled")            \
 _(ENQ_FAIL, "Enqueue failed to crypto device")     \
 _(DISCARD, "Not enough crypto operations, discarding frame")  \
 _(SESSION, "Failed to get crypto session")         \
 _(NOSUP, "Cipher/Auth not supported")


typedef enum
{
#define _(sym,str) ESP_ENCRYPT_ERROR_##sym,
  foreach_esp_encrypt_error
#undef _
    ESP_ENCRYPT_N_ERROR,
} esp_encrypt_error_t;

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

vlib_node_registration_t dpdk_esp_encrypt_node;

typedef struct
{
  ipsec_crypto_alg_t crypto_alg;
  ipsec_integ_alg_t integ_alg;
  u8 packet_data[64];
} esp_encrypt_trace_t;

/* packet trace format function */
static u8 *
format_esp_encrypt_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_encrypt_trace_t *t = va_arg (*args, esp_encrypt_trace_t *);
  ip4_header_t *ih4 = (ip4_header_t *) t->packet_data;
  u32 indent = format_get_indent (s), offset;

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

  if ((ih4->ip_version_and_header_length & 0xF0) == 0x60)
    {
      s = format (s, "%U%U", format_white_space, indent,
                  format_ip6_header, ih4);
      offset = sizeof (ip6_header_t);
    }
  else
    {
      s = format (s, "%U%U", format_white_space, indent,
                  format_ip4_header, ih4);
      offset = ip4_header_bytes (ih4);
    }

  s = format (s, "\n%U%U", format_white_space, indent,
              format_esp_header, t->packet_data + offset);

  return s;
}

static uword
dpdk_esp_encrypt_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_encrypt_node.index,
                                   ESP_ENCRYPT_ERROR_DISCARD, 1);
      /* Discard whole frame */
      return n_left_from;
    }

  next_index = ESP_ENCRYPT_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;
          vlib_buffer_t *b0 = 0;
          u32 sa_index0;
          ip4_and_esp_header_t *ih0, *oh0 = 0;
          ip6_and_esp_header_t *ih6_0, *oh6_0 = 0;
          ip4_and_udp_and_esp_header_t *ouh0 = 0;
          esp_header_t *esp0;
          esp_footer_t *f0;
          u8 is_ipv6, next_hdr_type;
          u32 iv_size;
          u16 orig_sz;
          u8 trunc_size;
          u16 rewrite_len;
          u16 udp_encap_adv = 0;
          struct rte_mbuf *mb0 = 0;
          struct rte_crypto_op *op;
          u16 res_idx;

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

          b0 = vlib_get_buffer (vm, bi0);
          ih0 = vlib_buffer_get_current (b0);
          mb0 = rte_mbuf_from_vlib_buffer (b0);

          /* ih0/ih6_0 */
          CLIB_PREFETCH (ih0, sizeof (ih6_0[0]), LOAD);
          /* f0 */
          CLIB_PREFETCH (vlib_buffer_get_tail (b0), 20, STORE);
          /* 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_encrypt_node.index,
                                               ESP_ENCRYPT_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, 1);
              if (PREDICT_FALSE (error || !session))
                {
                  clib_warning ("failed to get crypto session");
                  vlib_node_increment_counter (vm,
                                               dpdk_esp_encrypt_node.index,
                                               ESP_ENCRYPT_ERROR_SESSION, 1);
                  to_next[0] = bi0;
                  to_next += 1;
                  n_left_to_next -= 1;
                  goto trace;
                }

              last_sa_index = sa_index0;
            }

          if (PREDICT_FALSE (esp_seq_advance (sa0)))
            {
              clib_warning ("sequence number counter has cycled SPI %u",
                            sa0->spi);
              vlib_node_increment_counter (vm, dpdk_esp_encrypt_node.index,
                                           ESP_ENCRYPT_ERROR_SEQ_CYCLED, 1);
              //TODO: rekey SA
              to_next[0] = bi0;
              to_next += 1;
              n_left_to_next -= 1;
              goto trace;
            }

          orig_sz = b0->current_length;

          /* TODO multi-seg support - total_length_not_including_first_buffer */
          sa0->total_data_size += b0->current_length;

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

          dpdk_gcm_cnt_blk *icb = &priv->cb;

          crypto_set_icb (icb, sa0->salt, sa0->seq, sa0->seq_hi);

          is_ipv6 = (ih0->ip4.ip_version_and_header_length & 0xF0) == 0x60;

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

          /* if UDP encapsulation is used adjust the address of the IP header */
          if (sa0->udp_encap && !is_ipv6)
            udp_encap_adv = sizeof (udp_header_t);

          if (sa0->is_tunnel)
            {
              rewrite_len = 0;
              if (!is_ipv6 && !sa0->is_tunnel_ip6)      /* ip4inip4 */
                {
                  /* in tunnel mode send it back to FIB */
                  priv->next = DPDK_CRYPTO_INPUT_NEXT_IP4_LOOKUP;
                  u8 adv = sizeof (ip4_header_t) + udp_encap_adv +
                    sizeof (esp_header_t) + iv_size;
                  vlib_buffer_advance (b0, -adv);
                  oh0 = vlib_buffer_get_current (b0);
                  ouh0 = vlib_buffer_get_current (b0);
                  next_hdr_type = IP_PROTOCOL_IP_IN_IP;
                  /*
                   * oh0->ip4.ip_version_and_header_length = 0x45;
                   * oh0->ip4.tos = ih0->ip4.tos;
                   * oh0->ip4.fragment_id = 0;
                   * oh0->ip4.flags_and_fragment_offset = 0;
                   */
                  oh0->ip4.checksum_data_64[0] =
                    clib_host_to_net_u64 (0x45ULL << 56);
                  /*
                   * oh0->ip4.ttl = 254;
                   * oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
                   */
                  oh0->ip4.checksum_data_32[2] =
                    clib_host_to_net_u32 (0xfe320000);

                  oh0->ip4.src_address.as_u32 =
                    sa0->tunnel_src_addr.ip4.as_u32;
                  oh0->ip4.dst_address.as_u32 =
                    sa0->tunnel_dst_addr.ip4.as_u32;

                  if (sa0->udp_encap)
                    {
                      oh0->ip4.protocol = IP_PROTOCOL_UDP;
                      esp0 = &ouh0->esp;
                    }
                  else
                    esp0 = &oh0->esp;
                  esp0->spi = clib_host_to_net_u32 (sa0->spi);
                  esp0->seq = clib_host_to_net_u32 (sa0->seq);
                }
              else if (is_ipv6 && sa0->is_tunnel_ip6)   /* ip6inip6 */
                {
                  /* in tunnel mode send it back to FIB */
                  priv->next = DPDK_CRYPTO_INPUT_NEXT_IP6_LOOKUP;

                  u8 adv =
                    sizeof (ip6_header_t) + sizeof (esp_header_t) + iv_size;
                  vlib_buffer_advance (b0, -adv);
                  ih6_0 = (ip6_and_esp_header_t *) ih0;
                  oh6_0 = vlib_buffer_get_current (b0);

                  next_hdr_type = IP_PROTOCOL_IPV6;

                  oh6_0->ip6.ip_version_traffic_class_and_flow_label =
                    ih6_0->ip6.ip_version_traffic_class_and_flow_label;

                  oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_ESP;
                  oh6_0->ip6.hop_limit = 254;
                  oh6_0->ip6.src_address.as_u64[0] =
                    sa0->tunnel_src_addr.ip6.as_u64[0];
                  oh6_0->ip6.src_address.as_u64[1] =
                    sa0->tunnel_src_addr.ip6.as_u64[1];
                  oh6_0->ip6.dst_address.as_u64[0] =
                    sa0->tunnel_dst_addr.ip6.as_u64[0];
                  oh6_0->ip6.dst_address.as_u64[1] =
                    sa0->tunnel_dst_addr.ip6.as_u64[1];
                  esp0 = &oh6_0->esp;
                  oh6_0->esp.spi = clib_host_to_net_u32 (sa0->spi);
                  oh6_0->esp.seq = clib_host_to_net_u32 (sa0->seq);
                }
              else              /* unsupported ip4inip6, ip6inip4 */
                {
                  vlib_node_increment_counter (vm,
                                               dpdk_esp_encrypt_node.index,
                                               ESP_ENCRYPT_ERROR_NOSUP, 1);
                  to_next[0] = bi0;
                  to_next += 1;
                  n_left_to_next -= 1;
                  goto trace;
                }
              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
            }
          else                  /* transport mode */
            {
              priv->next = DPDK_CRYPTO_INPUT_NEXT_INTERFACE_OUTPUT;
              rewrite_len = vnet_buffer (b0)->ip.save_rewrite_length;
              u16 adv = sizeof (esp_header_t) + iv_size + udp_encap_adv;
              vlib_buffer_advance (b0, -adv - rewrite_len);
              u8 *src = ((u8 *) ih0) - rewrite_len;
              u8 *dst = vlib_buffer_get_current (b0);
              oh0 = vlib_buffer_get_current (b0) + rewrite_len;

              if (is_ipv6)
                {
                  orig_sz -= sizeof (ip6_header_t);
                  ih6_0 = (ip6_and_esp_header_t *) ih0;
                  next_hdr_type = ih6_0->ip6.protocol;
                  memmove (dst, src, rewrite_len + sizeof (ip6_header_t));
                  oh6_0 = (ip6_and_esp_header_t *) oh0;
                  oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_ESP;
                  esp0 = &oh6_0->esp;
                }
              else              /* ipv4 */
                {
                  u16 ip_size = ip4_header_bytes (&ih0->ip4);
                  orig_sz -= ip_size;
                  next_hdr_type = ih0->ip4.protocol;
                  memmove (dst, src, rewrite_len + ip_size);
                  oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
                  esp0 = (esp_header_t *) (((u8 *) oh0) + ip_size);
                  if (sa0->udp_encap)
                    {
                      oh0->ip4.protocol = IP_PROTOCOL_UDP;
                      esp0 = (esp_header_t *)
                        (((u8 *) oh0) + ip_size + udp_encap_adv);
                    }
                  else
                    {
                      oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
                      esp0 = (esp_header_t *) (((u8 *) oh0) + ip_size);
                    }
                }
              esp0->spi = clib_host_to_net_u32 (sa0->spi);
              esp0->seq = clib_host_to_net_u32 (sa0->seq);
            }

          if (sa0->udp_encap && ouh0)
            {
              ouh0->udp.src_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
              ouh0->udp.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
              ouh0->udp.checksum = 0;
            }
          ASSERT (is_pow2 (cipher_alg->boundary));
          u16 mask = cipher_alg->boundary - 1;
          u16 pad_payload_len = ((orig_sz + 2) + mask) & ~mask;
          u8 pad_bytes = pad_payload_len - 2 - orig_sz;

          u8 *padding =
            vlib_buffer_put_uninit (b0, pad_bytes + 2 + trunc_size);

          /* The extra pad bytes would be overwritten by the digest */
          if (pad_bytes)
            clib_memcpy (padding, pad_data, 16);

          f0 = (esp_footer_t *) (padding + pad_bytes);
          f0->pad_length = pad_bytes;
          f0->next_header = next_hdr_type;

          if (is_ipv6)
            {
              u16 len = b0->current_length - sizeof (ip6_header_t);
              oh6_0->ip6.payload_length =
                clib_host_to_net_u16 (len - rewrite_len);
            }
          else
            {
              oh0->ip4.length =
                clib_host_to_net_u16 (b0->current_length - rewrite_len);
              oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
              if (sa0->udp_encap && ouh0)
                {
                  ouh0->udp.length =
                    clib_host_to_net_u16 (clib_net_to_host_u16
                                          (ouh0->ip4.length) -
                                          ip4_header_bytes (&ouh0->ip4));
                }
            }

          vnet_buffer (b0)->sw_if_index[VLIB_RX] =
            vnet_buffer (b0)->sw_if_index[VLIB_RX];
          b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;

          /* mbuf packet starts at ESP header */
          mb0->data_len = vlib_buffer_get_tail (b0) - ((u8 *) esp0);
          mb0->pkt_len = vlib_buffer_get_tail (b0) - ((u8 *) esp0);
          mb0->data_off = ((void *) esp0) - mb0->buf_addr;

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

          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)
            {
              cipher_off = sizeof (esp_header_t);
              cipher_len = iv_size + pad_payload_len;
            }
          else                  /* CTR/GCM */
            {
              u32 *esp_iv = (u32 *) (esp0 + 1);
              esp_iv[0] = sa0->seq;
              esp_iv[1] = sa0->seq_hi;

              cipher_off = sizeof (esp_header_t) + iv_size;
              cipher_len = pad_payload_len;
            }

          if (is_aead)
            {
              aad = (u32 *) priv->aad;
              aad[0] = clib_host_to_net_u32 (sa0->spi);
              aad[1] = clib_host_to_net_u32 (sa0->seq);

              /* 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 =
                vlib_buffer_get_tail (b0) - ((u8 *) esp0) - trunc_size;
              if (sa0->use_esn)
                {
                  u32 *_digest = (u32 *) digest;
                  _digest[0] = clib_host_to_net_u32 (sa0->seq_hi);
                  auth_len += 4;
                }
            }

          crypto_op_setup (is_aead, mb0, op, session, cipher_off, cipher_len,
                           0, auth_len, (u8 *) aad, digest, digest_paddr);

        trace:
          if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
            {
              esp_encrypt_trace_t *tr =
                vlib_add_trace (vm, node, b0, sizeof (*tr));
              tr->crypto_alg = sa0->crypto_alg;
              tr->integ_alg = sa0->integ_alg;
              u8 *p = vlib_buffer_get_current (b0);
              if (!sa0->is_tunnel)
                p += vnet_buffer (b0)->ip.save_rewrite_length;
              clib_memcpy (tr->packet_data, p, sizeof (tr->packet_data));
            }
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }
  vlib_node_increment_counter (vm, dpdk_esp_encrypt_node.index,
                               ESP_ENCRYPT_ERROR_RX_PKTS,
                               from_frame->n_vectors);

  crypto_enqueue_ops (vm, cwm, 1, dpdk_esp_encrypt_node.index,
                      ESP_ENCRYPT_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_encrypt_node) = {
  .function = dpdk_esp_encrypt_node_fn,
  .name = "dpdk-esp-encrypt",
  .flags = VLIB_NODE_FLAG_IS_OUTPUT,
  .vector_size = sizeof (u32),
  .format_trace = format_esp_encrypt_trace,
  .n_errors = ARRAY_LEN (esp_encrypt_error_strings),
  .error_strings = esp_encrypt_error_strings,
  .n_next_nodes = 1,
  .next_nodes =
    {
      [ESP_ENCRYPT_NEXT_DROP] = "error-drop",
    }
};
/* *INDENT-ON* */

VLIB_NODE_FUNCTION_MULTIARCH (dpdk_esp_encrypt_node, dpdk_esp_encrypt_node_fn)
/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */