text: /*
   * esp_encrypt.c : IPSec ESP encrypt 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>
  
  ipsec_proto_main_t ipsec_proto_main;
  
  #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")                    \
   _(NO_BUFFER, "No buffer (packet dropped)")         \
   _(DECRYPTION_FAILED, "ESP encryption failed")      \
   _(SEQ_CYCLED, "sequence number cycled")
  
  
  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 esp_encrypt_node;
  
  typedef struct
  {
    u32 spi;
    u32 seq;
    ipsec_crypto_alg_t crypto_alg;
    ipsec_integ_alg_t integ_alg;
  } 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 *);
  
    s = format (s, "esp: spi %u seq %u crypto %U integrity %U",
  	      t->spi, t->seq,
  	      format_ipsec_crypto_alg, t->crypto_alg,
  	      format_ipsec_integ_alg, t->integ_alg);
    return s;
  }
  
  always_inline void
  esp_encrypt_cbc (ipsec_crypto_alg_t alg,
  		 u8 * in, u8 * out, size_t in_len, u8 * key, u8 * iv)
  {
    ipsec_proto_main_t *em = &ipsec_proto_main;
    u32 thread_index = vlib_get_thread_index ();
  #if OPENSSL_VERSION_NUMBER >= 0x10100000L
    EVP_CIPHER_CTX *ctx = em->per_thread_data[thread_index].encrypt_ctx;
  #else
    EVP_CIPHER_CTX *ctx = &(em->per_thread_data[thread_index].encrypt_ctx);
  #endif
    const EVP_CIPHER *cipher = NULL;
    int out_len;
  
    ASSERT (alg < IPSEC_CRYPTO_N_ALG);
  
    if (PREDICT_FALSE
        (em->ipsec_proto_main_crypto_algs[alg].type == IPSEC_CRYPTO_ALG_NONE))
      return;
  
    if (PREDICT_FALSE
        (alg != em->per_thread_data[thread_index].last_encrypt_alg))
      {
        cipher = em->ipsec_proto_main_crypto_algs[alg].type;
        em->per_thread_data[thread_index].last_encrypt_alg = alg;
      }
  
    EVP_EncryptInit_ex (ctx, cipher, NULL, key, iv);
  
    EVP_EncryptUpdate (ctx, out, &out_len, in, in_len);
    EVP_EncryptFinal_ex (ctx, out + out_len, &out_len);
  }
  
  static uword
  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 = 0, next_index;
    from = vlib_frame_vector_args (from_frame);
    n_left_from = from_frame->n_vectors;
    ipsec_main_t *im = &ipsec_main;
    ipsec_proto_main_t *em = &ipsec_proto_main;
    u32 *recycle = 0;
    u32 thread_index = vlib_get_thread_index ();
  
    ipsec_alloc_empty_buffers (vm, im);
  
    u32 *empty_buffers = im->empty_buffers[thread_index];
  
    if (PREDICT_FALSE (vec_len (empty_buffers) < n_left_from))
      {
        vlib_node_increment_counter (vm, esp_encrypt_node.index,
  				   ESP_ENCRYPT_ERROR_NO_BUFFER, n_left_from);
        clib_warning ("no enough empty buffers. discarding frame");
        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, next0;
  	  vlib_buffer_t *i_b0, *o_b0 = 0;
  	  u32 sa_index0;
  	  ipsec_sa_t *sa0;
  	  ip4_and_esp_header_t *ih0, *oh0 = 0;
  	  ip6_and_esp_header_t *ih6_0, *oh6_0 = 0;
  	  uword last_empty_buffer;
  	  esp_header_t *o_esp0;
  	  esp_footer_t *f0;
  	  u8 is_ipv6;
  	  u8 ip_hdr_size;
  	  u8 next_hdr_type;
  	  u32 ip_proto = 0;
  	  u8 transport_mode = 0;
  
  	  i_bi0 = from[0];
  	  from += 1;
  	  n_left_from -= 1;
  	  n_left_to_next -= 1;
  
  	  next0 = ESP_ENCRYPT_NEXT_DROP;
  
  	  i_b0 = vlib_get_buffer (vm, i_bi0);
  	  sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
  	  sa0 = pool_elt_at_index (im->sad, 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, esp_encrypt_node.index,
  					   ESP_ENCRYPT_ERROR_SEQ_CYCLED, 1);
  	      //TODO: rekey SA
  	      o_bi0 = i_bi0;
  	      to_next[0] = o_bi0;
  	      to_next += 1;
  	      goto trace;
  	    }
  
  	  sa0->total_data_size += i_b0->current_length;
  
  	  /* grab free buffer */
  	  last_empty_buffer = vec_len (empty_buffers) - 1;
  	  o_bi0 = empty_buffers[last_empty_buffer];
  	  o_b0 = vlib_get_buffer (vm, o_bi0);
  	  o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
  	  o_b0->current_data = sizeof (ethernet_header_t);
  	  ih0 = vlib_buffer_get_current (i_b0);
  	  vlib_prefetch_buffer_with_index (vm,
  					   empty_buffers[last_empty_buffer -
  							 1], STORE);
  	  _vec_len (empty_buffers) = last_empty_buffer;
  	  to_next[0] = o_bi0;
  	  to_next += 1;
  
  	  /* add old buffer to the recycle list */
  	  vec_add1 (recycle, i_bi0);
  
  	  /* is ipv6 */
  	  if (PREDICT_FALSE
  	      ((ih0->ip4.ip_version_and_header_length & 0xF0) == 0x60))
  	    {
  	      is_ipv6 = 1;
  	      ih6_0 = vlib_buffer_get_current (i_b0);
  	      ip_hdr_size = sizeof (ip6_header_t);
  	      next_hdr_type = IP_PROTOCOL_IPV6;
  	      oh6_0 = vlib_buffer_get_current (o_b0);
  	      o_esp0 = vlib_buffer_get_current (o_b0) + sizeof (ip6_header_t);
  
  	      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] =
  		ih6_0->ip6.src_address.as_u64[0];
  	      oh6_0->ip6.src_address.as_u64[1] =
  		ih6_0->ip6.src_address.as_u64[1];
  	      oh6_0->ip6.dst_address.as_u64[0] =
  		ih6_0->ip6.dst_address.as_u64[0];
  	      oh6_0->ip6.dst_address.as_u64[1] =
  		ih6_0->ip6.dst_address.as_u64[1];
  	      oh6_0->esp.spi = clib_net_to_host_u32 (sa0->spi);
  	      oh6_0->esp.seq = clib_net_to_host_u32 (sa0->seq);
  	      ip_proto = ih6_0->ip6.protocol;
  
  	      next0 = ESP_ENCRYPT_NEXT_IP6_LOOKUP;
  	    }
  	  else
  	    {
  	      is_ipv6 = 0;
  	      ip_hdr_size = sizeof (ip4_header_t);
  	      next_hdr_type = IP_PROTOCOL_IP_IN_IP;
  	      oh0 = vlib_buffer_get_current (o_b0);
  	      o_esp0 = vlib_buffer_get_current (o_b0) + sizeof (ip4_header_t);
  
  	      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.ttl = 254;
  	      oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
  	      oh0->ip4.src_address.as_u32 = ih0->ip4.src_address.as_u32;
  	      oh0->ip4.dst_address.as_u32 = ih0->ip4.dst_address.as_u32;
  	      oh0->esp.spi = clib_net_to_host_u32 (sa0->spi);
  	      oh0->esp.seq = clib_net_to_host_u32 (sa0->seq);
  	      ip_proto = ih0->ip4.protocol;
  
  	      next0 = ESP_ENCRYPT_NEXT_IP4_LOOKUP;
  	    }
  
  	  if (PREDICT_TRUE
  	      (!is_ipv6 && sa0->is_tunnel && !sa0->is_tunnel_ip6))
  	    {
  	      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;
  
  	      vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
  	    }
  	  else if (is_ipv6 && sa0->is_tunnel && sa0->is_tunnel_ip6)
  	    {
  	      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];
  
  	      vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
  	    }
  	  else
  	    {
  	      next_hdr_type = ip_proto;
  	      if (vnet_buffer (i_b0)->sw_if_index[VLIB_TX] != ~0)
  		{
  		  transport_mode = 1;
  		  ethernet_header_t *ieh0, *oeh0;
  		  ieh0 =
  		    (ethernet_header_t *) ((u8 *)
  					   vlib_buffer_get_current (i_b0) -
  					   sizeof (ethernet_header_t));
  		  oeh0 = (ethernet_header_t *) o_b0->data;
  		  clib_memcpy (oeh0, ieh0, sizeof (ethernet_header_t));
  		  next0 = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
  		  vnet_buffer (o_b0)->sw_if_index[VLIB_TX] =
  		    vnet_buffer (i_b0)->sw_if_index[VLIB_TX];
  		}
  	      vlib_buffer_advance (i_b0, ip_hdr_size);
  	    }
  
  	  ASSERT (sa0->crypto_alg < IPSEC_CRYPTO_N_ALG);
  
  	  if (PREDICT_TRUE (sa0->crypto_alg != IPSEC_CRYPTO_ALG_NONE))
  	    {
  
  	      const int BLOCK_SIZE =
  		em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].block_size;
  	      const int IV_SIZE =
  		em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size;
  	      int blocks = 1 + (i_b0->current_length + 1) / BLOCK_SIZE;
  
  	      /* pad packet in input buffer */
  	      u8 pad_bytes = BLOCK_SIZE * blocks - 2 - i_b0->current_length;
  	      u8 i;
  	      u8 *padding =
  		vlib_buffer_get_current (i_b0) + i_b0->current_length;
  	      i_b0->current_length = BLOCK_SIZE * blocks;
  	      for (i = 0; i < pad_bytes; ++i)
  		{
  		  padding[i] = i + 1;
  		}
  	      f0 = vlib_buffer_get_current (i_b0) + i_b0->current_length - 2;
  	      f0->pad_length = pad_bytes;
  	      f0->next_header = next_hdr_type;
  
  	      o_b0->current_length = ip_hdr_size + sizeof (esp_header_t) +
  		BLOCK_SIZE * blocks + IV_SIZE;
  
  	      vnet_buffer (o_b0)->sw_if_index[VLIB_RX] =
  		vnet_buffer (i_b0)->sw_if_index[VLIB_RX];
  
  	      u8 iv[em->
  		    ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size];
  	      RAND_bytes (iv, sizeof (iv));
  
  	      clib_memcpy ((u8 *) vlib_buffer_get_current (o_b0) +
  			   ip_hdr_size + sizeof (esp_header_t), iv,
  			   em->ipsec_proto_main_crypto_algs[sa0->
  							    crypto_alg].iv_size);
  
  	      esp_encrypt_cbc (sa0->crypto_alg,
  			       (u8 *) vlib_buffer_get_current (i_b0),
  			       (u8 *) vlib_buffer_get_current (o_b0) +
  			       ip_hdr_size + sizeof (esp_header_t) +
  			       IV_SIZE, BLOCK_SIZE * blocks,
  			       sa0->crypto_key, iv);
  	    }
  
  	  o_b0->current_length += hmac_calc (sa0->integ_alg, sa0->integ_key,
  					     sa0->integ_key_len,
  					     (u8 *) o_esp0,
  					     o_b0->current_length -
  					     ip_hdr_size,
  					     vlib_buffer_get_current (o_b0) +
  					     o_b0->current_length,
  					     sa0->use_esn, sa0->seq_hi);
  
  
  	  if (PREDICT_FALSE (is_ipv6))
  	    {
  	      oh6_0->ip6.payload_length =
  		clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0) -
  				      sizeof (ip6_header_t));
  	    }
  	  else
  	    {
  	      oh0->ip4.length =
  		clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0));
  	      oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
  	    }
  
  	  if (transport_mode)
  	    vlib_buffer_reset (o_b0);
  
  	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_encrypt_trace_t *tr =
  		    vlib_add_trace (vm, node, o_b0, sizeof (*tr));
  		  tr->spi = sa0->spi;
  		  tr->seq = sa0->seq - 1;
  		  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_encrypt_node.index,
  			       ESP_ENCRYPT_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_encrypt_node) = {
    .function = esp_encrypt_node_fn,
    .name = "esp-encrypt",
    .vector_size = sizeof (u32),
    .format_trace = format_esp_encrypt_trace,
    .type = VLIB_NODE_TYPE_INTERNAL,
  
    .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
    .error_strings = esp_encrypt_error_strings,
  
    .n_next_nodes = ESP_ENCRYPT_N_NEXT,
    .next_nodes = {
  #define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
      foreach_esp_encrypt_next
  #undef _
    },
  };
  /* *INDENT-ON* */
  
  VLIB_NODE_FUNCTION_MULTIARCH (esp_encrypt_node, esp_encrypt_node_fn)
  /*
   * fd.io coding-style-patch-verification: ON
   *
   * Local Variables:
   * eval: (c-set-style "gnu")
   * End:
   */
  