text: /*
   * Copyright (c) 2016 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.
   */
  /**
   * @file
   * @brief L2-GRE over IPSec packet processing.
   *
   * Add GRE header to thr packet and send it to the esp-encrypt node.
  */
  
  #include <vnet/vnet.h>
  #include <vnet/ipsec-gre/ipsec_gre.h>
  
  extern ipsec_gre_main_t ipsec_gre_main;
  
  #ifndef CLIB_MARCH_VARIANT
  ipsec_gre_main_t ipsec_gre_main;
  #endif /* CLIB_MARCH_VARIANT */
  
  /**
   * @brief IPv4 and GRE header union.
   *
  */
  typedef struct
  {
    union
    {
      ip4_and_gre_header_t ip4_and_gre;
      u64 as_u64[3];
    };
  } ip4_and_gre_union_t;
  
  /**
   * @brief Packet trace.
   *
  */
  typedef struct
  {
    u32 tunnel_id; /**< Tunnel-id / index in tunnel vector */
  
    u32 length; /**< pkt length */
  
    ip4_address_t src; /**< tunnel src IPv4 address */
    ip4_address_t dst; /**< tunnel dst IPv4 address */
  
    u32 sa_id; /**< tunnel IPSec SA id */
  } ipsec_gre_tx_trace_t;
  
  static u8 *
  format_ipsec_gre_tx_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 *);
    ipsec_gre_tx_trace_t *t = va_arg (*args, ipsec_gre_tx_trace_t *);
  
    s = format (s, "GRE: tunnel %d len %d src %U dst %U sa-id %d",
  	      t->tunnel_id, clib_net_to_host_u16 (t->length),
  	      format_ip4_address, &t->src.as_u8,
  	      format_ip4_address, &t->dst.as_u8, t->sa_id);
    return s;
  }
  
  /**
   * @brief IPSec-GRE tunnel interface tx function.
   *
   * Add GRE header to the packet.
   *
   * @param vm vlib_main_t corresponding to the current thread.
   * @param node vlib_node_runtime_t data for this node.
   * @param frame vlib_frame_t whose contents should be dispatched.
   *
   * @par Graph mechanics: buffer metadata, next index usage
   *
   * <em>Uses:</em>
   * - <code>node->runtime_data</code>
   *     - Match tunnel by <code>rd->dev_instance</code> in IPSec-GRE tunnels
   *       pool.
   *
   * <em>Sets:</em>
   * - <code>vnet_buffer(b)->output_features.ipsec_sad_index</code>
   *     - Set IPSec Security Association for packet encryption.
   * - <code>vnet_buffer(b)->sw_if_index[VLIB_TX]</code>
   *     - Reset output sw_if_index.
   *
   * <em>Next Index:</em>
   * - Dispatches the packet to the esp-encrypt node.
  */
  VNET_DEVICE_CLASS_TX_FN (ipsec_gre_device_class) (vlib_main_t * vm,
  						  vlib_node_runtime_t * node,
  						  vlib_frame_t * frame)
  {
    ipsec_gre_main_t *igm = &ipsec_gre_main;
    u32 next_index;
    u32 *from, *to_next, n_left_from, n_left_to_next;
    vnet_interface_output_runtime_t *rd = (void *) node->runtime_data;
    ipsec_gre_tunnel_t *t = pool_elt_at_index (igm->tunnels, rd->dev_instance);
  
    u16 l2_gre_protocol_ethertype = clib_net_to_host_u16 (GRE_PROTOCOL_teb);
  
    /* Vector of buffer / pkt indices we're supposed to process */
    from = vlib_frame_vector_args (frame);
  
    /* Number of buffers / pkts */
    n_left_from = frame->n_vectors;
  
    /* Speculatively send the first buffer to the last disposition we used */
    next_index = node->cached_next_index;
  
    while (n_left_from > 0)
      {
        /* set up to enqueue to our disposition with index = next_index */
        vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  
        /*
         * As long as we have enough pkts left to process two pkts
         * and prefetch two pkts...
         */
        while (n_left_from >= 4 && n_left_to_next >= 2)
  	{
  	  vlib_buffer_t *b0, *b1;
  	  ip4_header_t *ip0, *ip1;
  	  ip4_and_gre_union_t *h0, *h1;
  	  u32 bi0, next0, bi1, next1;
  	  __attribute__ ((unused)) u8 error0, error1;
  
  	  /* Prefetch the next iteration */
  	  {
  	    vlib_buffer_t *p2, *p3;
  
  	    p2 = vlib_get_buffer (vm, from[2]);
  	    p3 = vlib_get_buffer (vm, from[3]);
  
  	    vlib_prefetch_buffer_header (p2, LOAD);
  	    vlib_prefetch_buffer_header (p3, LOAD);
  
  	    /*
  	     * Prefetch packet data. We expect to overwrite
  	     * the inbound L2 header with an ip header and a
  	     * gre header. Might want to prefetch the last line
  	     * of rewrite space as well; need profile data
  	     */
  	    CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
  	    CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
  	  }
  
  	  /* Pick up the next two buffer indices */
  	  bi0 = from[0];
  	  bi1 = from[1];
  
  	  /* Speculatively enqueue them where we sent the last buffer */
  	  to_next[0] = bi0;
  	  to_next[1] = bi1;
  	  from += 2;
  	  to_next += 2;
  	  n_left_to_next -= 2;
  	  n_left_from -= 2;
  
  	  b0 = vlib_get_buffer (vm, bi0);
  	  b1 = vlib_get_buffer (vm, bi1);
  
  	  vlib_buffer_advance (b0, -sizeof (*h0));
  	  vlib_buffer_advance (b1, -sizeof (*h1));
  
  	  h0 = vlib_buffer_get_current (b0);
  	  h1 = vlib_buffer_get_current (b1);
  	  h0->as_u64[0] = 0;
  	  h0->as_u64[1] = 0;
  	  h0->as_u64[2] = 0;
  
  	  h1->as_u64[0] = 0;
  	  h1->as_u64[1] = 0;
  	  h1->as_u64[2] = 0;
  
  	  ip0 = &h0->ip4_and_gre.ip4;
  	  h0->ip4_and_gre.gre.protocol = l2_gre_protocol_ethertype;
  	  ip0->ip_version_and_header_length = 0x45;
  	  ip0->ttl = 254;
  	  ip0->protocol = IP_PROTOCOL_GRE;
  
  	  ip1 = &h1->ip4_and_gre.ip4;
  	  h1->ip4_and_gre.gre.protocol = l2_gre_protocol_ethertype;
  	  ip1->ip_version_and_header_length = 0x45;
  	  ip1->ttl = 254;
  	  ip1->protocol = IP_PROTOCOL_GRE;
  
  	  ip0->length =
  	    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
  	  ip1->length =
  	    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b1));
  	  ip0->src_address.as_u32 = t->tunnel_src.as_u32;
  	  ip1->src_address.as_u32 = t->tunnel_src.as_u32;
  	  ip0->dst_address.as_u32 = t->tunnel_dst.as_u32;
  	  ip1->dst_address.as_u32 = t->tunnel_dst.as_u32;
  	  ip0->checksum = ip4_header_checksum (ip0);
  	  ip1->checksum = ip4_header_checksum (ip1);
  
  	  vnet_buffer (b0)->sw_if_index[VLIB_RX] =
  	    vnet_buffer (b0)->sw_if_index[VLIB_TX];
  	  vnet_buffer (b1)->sw_if_index[VLIB_RX] =
  	    vnet_buffer (b1)->sw_if_index[VLIB_TX];
  
  	  vnet_buffer (b0)->ipsec.sad_index = t->local_sa;
  	  vnet_buffer (b1)->ipsec.sad_index = t->local_sa;
  
  	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
  	  vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
  
  	  next0 = IPSEC_GRE_OUTPUT_NEXT_ESP_ENCRYPT;
  	  next1 = IPSEC_GRE_OUTPUT_NEXT_ESP_ENCRYPT;
  	  error0 = IPSEC_GRE_ERROR_NONE;
  	  error1 = IPSEC_GRE_ERROR_NONE;
  
  	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
  	    {
  	      ipsec_gre_tx_trace_t *tr = vlib_add_trace (vm, node,
  							 b0, sizeof (*tr));
  	      tr->tunnel_id = t - igm->tunnels;
  	      tr->length = ip0->length;
  	      tr->src.as_u32 = ip0->src_address.as_u32;
  	      tr->dst.as_u32 = ip0->dst_address.as_u32;
  	      tr->sa_id = t->local_sa_id;
  	    }
  
  	  if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED))
  	    {
  	      ipsec_gre_tx_trace_t *tr = vlib_add_trace (vm, node,
  							 b1, sizeof (*tr));
  	      tr->tunnel_id = t - igm->tunnels;
  	      tr->length = ip1->length;
  	      tr->src.as_u32 = ip1->src_address.as_u32;
  	      tr->dst.as_u32 = ip1->dst_address.as_u32;
  	      tr->sa_id = t->local_sa_id;
  	    }
  
  	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
  					   to_next, n_left_to_next,
  					   bi0, bi1, next0, next1);
  	}
  
        while (n_left_from > 0 && n_left_to_next > 0)
  	{
  	  vlib_buffer_t *b0;
  	  ip4_header_t *ip0;
  	  ip4_and_gre_union_t *h0;
  	  u32 bi0, next0;
  	  __attribute__ ((unused)) u8 error0;
  
  	  bi0 = to_next[0] = from[0];
  	  from += 1;
  	  n_left_from -= 1;
  	  to_next += 1;
  	  n_left_to_next -= 1;
  
  	  b0 = vlib_get_buffer (vm, bi0);
  
  	  vlib_buffer_advance (b0, -sizeof (*h0));
  
  	  h0 = vlib_buffer_get_current (b0);
  	  h0->as_u64[0] = 0;
  	  h0->as_u64[1] = 0;
  	  h0->as_u64[2] = 0;
  
  	  ip0 = &h0->ip4_and_gre.ip4;
  	  h0->ip4_and_gre.gre.protocol = l2_gre_protocol_ethertype;
  	  ip0->ip_version_and_header_length = 0x45;
  	  ip0->ttl = 254;
  	  ip0->protocol = IP_PROTOCOL_GRE;
  	  ip0->length =
  	    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
  	  ip0->src_address.as_u32 = t->tunnel_src.as_u32;
  	  ip0->dst_address.as_u32 = t->tunnel_dst.as_u32;
  	  ip0->checksum = ip4_header_checksum (ip0);
  
  	  vnet_buffer (b0)->sw_if_index[VLIB_RX] =
  	    vnet_buffer (b0)->sw_if_index[VLIB_TX];
  	  vnet_buffer (b0)->ipsec.sad_index = t->local_sa;
  	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
  
  	  next0 = IPSEC_GRE_OUTPUT_NEXT_ESP_ENCRYPT;
  	  error0 = IPSEC_GRE_ERROR_NONE;
  
  	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
  	    {
  	      ipsec_gre_tx_trace_t *tr = vlib_add_trace (vm, node,
  							 b0, sizeof (*tr));
  	      tr->tunnel_id = t - igm->tunnels;
  	      tr->length = ip0->length;
  	      tr->src.as_u32 = ip0->src_address.as_u32;
  	      tr->dst.as_u32 = ip0->dst_address.as_u32;
  	      tr->sa_id = t->local_sa_id;
  	    }
  
  	  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, ipsec_gre_input_node.index,
  			       IPSEC_GRE_ERROR_PKTS_ENCAP, frame->n_vectors);
  
    return frame->n_vectors;
  }
  
  static clib_error_t *
  ipsec_gre_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index,
  				   u32 flags)
  {
    if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
      vnet_hw_interface_set_flags (vnm, hw_if_index,
  				 VNET_HW_INTERFACE_FLAG_LINK_UP);
    else
      vnet_hw_interface_set_flags (vnm, hw_if_index, 0 /* down */ );
  
    return /* no error */ 0;
  }
  
  static u8 *
  format_ipsec_gre_tunnel_name (u8 * s, va_list * args)
  {
    u32 dev_instance = va_arg (*args, u32);
    return format (s, "ipsec-gre%d", dev_instance);
  }
  
  static u8 *
  format_ipsec_gre_device (u8 * s, va_list * args)
  {
    u32 dev_instance = va_arg (*args, u32);
    CLIB_UNUSED (int verbose) = va_arg (*args, int);
  
    s = format (s, "IPSEC-GRE tunnel: id %d\n", dev_instance);
    return s;
  }
  
  /* *INDENT-OFF* */
  VNET_DEVICE_CLASS (ipsec_gre_device_class) = {
    .name = "IPSec GRE tunnel device",
    .format_device_name = format_ipsec_gre_tunnel_name,
    .format_device = format_ipsec_gre_device,
    .format_tx_trace = format_ipsec_gre_tx_trace,
    .admin_up_down_function = ipsec_gre_interface_admin_up_down,
  };
  
  
  #ifndef CLIB_MARCH_VARIANT
  VNET_HW_INTERFACE_CLASS (ipsec_gre_hw_interface_class) = {
    .name = "IPSEC-GRE",
  };
  #endif /* CLIB_MARCH_VARIANT */
  /* *INDENT-ON* */
  
  static clib_error_t *
  ipsec_gre_init (vlib_main_t * vm)
  {
    ipsec_gre_main_t *igm = &ipsec_gre_main;
    clib_error_t *error;
  
    clib_memset (igm, 0, sizeof (igm[0]));
    igm->vlib_main = vm;
    igm->vnet_main = vnet_get_main ();
  
    if ((error = vlib_call_init_function (vm, ip_main_init)))
      return error;
  
    if ((error = vlib_call_init_function (vm, ip4_lookup_init)))
      return error;
  
    igm->tunnel_by_key = hash_create (0, sizeof (uword));
  
    return vlib_call_init_function (vm, ipsec_gre_input_init);
  }
  
  VLIB_INIT_FUNCTION (ipsec_gre_init);
  
  /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
  