src/vnet/devices/af_packet/node.c - fdio/vpp - Gitiles

 /*
  *------------------------------------------------------------------
  * af_packet.c - linux kernel packet interface
  *
  * 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.
  *------------------------------------------------------------------
  */

 #include <linux/if_packet.h>

 #include <vlib/vlib.h>
 #include <vlib/unix/unix.h>
 #include <vnet/ip/ip.h>
 #include <vnet/ethernet/ethernet.h>
 #include <vnet/interface/rx_queue_funcs.h>
 #include <vnet/feature/feature.h>
 #include <vnet/ethernet/packet.h>

 #include <vnet/devices/af_packet/af_packet.h>
 #include <vnet/devices/virtio/virtio_std.h>

 #define foreach_af_packet_input_error                                         \
   _ (PARTIAL_PKT, "partial packet")                                           \
   _ (TIMEDOUT_BLK, "timed out block")                                         \
   _ (TOTAL_RECV_BLK, "total received block")
 typedef enum
 {
 #define _(f,s) AF_PACKET_INPUT_ERROR_##f,
   foreach_af_packet_input_error
 #undef _
     AF_PACKET_INPUT_N_ERROR,
 } af_packet_input_error_t;

 static char *af_packet_input_error_strings[] = {
 #define _(n,s) s,
   foreach_af_packet_input_error
 #undef _
 };

 typedef struct
 {
   u32 next_index;
   u32 hw_if_index;
   u16 queue_id;
   int block;
   u32 pkt_num;
   void *block_start;
   block_desc_t bd;
   tpacket3_hdr_t tph;
   vnet_virtio_net_hdr_t vnet_hdr;
 } af_packet_input_trace_t;

 static u8 *
 format_af_packet_input_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 *);
   af_packet_input_trace_t *t = va_arg (*args, af_packet_input_trace_t *);
   u32 indent = format_get_indent (s);

   s = format (s, "af_packet: hw_if_index %d rx-queue %u next-index %d",
 	      t->hw_if_index, t->queue_id, t->next_index);

   s = format (
     s, "\n%Ublock %u:\n%Uaddress %p version %u seq_num %lu pkt_num %u",
     format_white_space, indent + 2, t->block, format_white_space, indent + 4,
     t->block_start, t->bd.version, t->bd.hdr.bh1.seq_num, t->pkt_num);
   s =
     format (s,
 	    "\n%Utpacket3_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
 	    "\n%Usec 0x%x nsec 0x%x vlan %U"
 #ifdef TP_STATUS_VLAN_TPID_VALID
 	    " vlan_tpid %u"
 #endif
 	    ,
 	    format_white_space, indent + 2, format_white_space, indent + 4,
 	    t->tph.tp_status, t->tph.tp_len, t->tph.tp_snaplen, t->tph.tp_mac,
 	    t->tph.tp_net, format_white_space, indent + 4, t->tph.tp_sec,
 	    t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.hv1.tp_vlan_tci
 #ifdef TP_STATUS_VLAN_TPID_VALID
 	    ,
 	    t->tph.hv1.tp_vlan_tpid
 #endif
     );

   s = format (s,
 	      "\n%Uvnet-hdr:\n%Uflags 0x%02x gso_type 0x%02x hdr_len %u"
 	      "\n%Ugso_size %u csum_start %u csum_offset %u",
 	      format_white_space, indent + 2, format_white_space, indent + 4,
 	      t->vnet_hdr.flags, t->vnet_hdr.gso_type, t->vnet_hdr.hdr_len,
 	      format_white_space, indent + 4, t->vnet_hdr.gso_size,
 	      t->vnet_hdr.csum_start, t->vnet_hdr.csum_offset);
   return s;
 }

 always_inline void
 buffer_add_to_chain (vlib_buffer_t *b, vlib_buffer_t *first_b,
 		     vlib_buffer_t *prev_b, u32 bi)
 {
   /* update first buffer */
   first_b->total_length_not_including_first_buffer += b->current_length;

   /* update previous buffer */
   prev_b->next_buffer = bi;
   prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;

   /* update current buffer */
   b->next_buffer = ~0;
 }

 static_always_inline void
 fill_gso_offload (vlib_buffer_t *b, u32 gso_size, u8 l4_hdr_sz)
 {
   b->flags |= VNET_BUFFER_F_GSO;
   vnet_buffer2 (b)->gso_size = gso_size;
   vnet_buffer2 (b)->gso_l4_hdr_sz = l4_hdr_sz;
 }

 static_always_inline void
 fill_cksum_offload (vlib_buffer_t *b, u8 *l4_hdr_sz, u8 is_ip)
 {
   vnet_buffer_oflags_t oflags = 0;
   u16 l2hdr_sz = 0;
   u16 ethertype = 0;
   u8 l4_proto = 0;

   if (is_ip)
     {
       switch (b->data[0] & 0xf0)
 	{
 	case 0x40:
 	  ethertype = ETHERNET_TYPE_IP4;
 	  break;
 	case 0x60:
 	  ethertype = ETHERNET_TYPE_IP6;
 	  break;
 	}
     }
   else
     {
       ethernet_header_t *eth = vlib_buffer_get_current (b);
       ethertype = clib_net_to_host_u16 (eth->type);
       l2hdr_sz = sizeof (ethernet_header_t);
       if (ethernet_frame_is_tagged (ethertype))
 	{
 	  ethernet_vlan_header_t *vlan = (ethernet_vlan_header_t *) (eth + 1);

 	  ethertype = clib_net_to_host_u16 (vlan->type);
 	  l2hdr_sz += sizeof (*vlan);
 	  if (ethertype == ETHERNET_TYPE_VLAN)
 	    {
 	      vlan++;
 	      ethertype = clib_net_to_host_u16 (vlan->type);
 	      l2hdr_sz += sizeof (*vlan);
 	    }
 	}
     }

   vnet_buffer (b)->l2_hdr_offset = 0;
   vnet_buffer (b)->l3_hdr_offset = l2hdr_sz;

   if (ethertype == ETHERNET_TYPE_IP4)
     {
       ip4_header_t *ip4 = (vlib_buffer_get_current (b) + l2hdr_sz);
       vnet_buffer (b)->l4_hdr_offset = l2hdr_sz + ip4_header_bytes (ip4);
       b->flags |= (VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_L2_HDR_OFFSET_VALID |
 		   VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
 		   VNET_BUFFER_F_L4_HDR_OFFSET_VALID);

       l4_proto = ip4->protocol;
     }
   else if (ethertype == ETHERNET_TYPE_IP6)
     {
       ip6_header_t *ip6 = (vlib_buffer_get_current (b) + l2hdr_sz);
       b->flags |= (VNET_BUFFER_F_IS_IP6 | VNET_BUFFER_F_L2_HDR_OFFSET_VALID |
 		   VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
 		   VNET_BUFFER_F_L4_HDR_OFFSET_VALID);
       u16 ip6_hdr_len = sizeof (ip6_header_t);

       if (ip6_ext_hdr (ip6->protocol))
 	{
 	  ip6_ext_header_t *p = (void *) (ip6 + 1);
 	  ip6_hdr_len += ip6_ext_header_len (p);
 	  while (ip6_ext_hdr (p->next_hdr))
 	    {
 	      ip6_hdr_len += ip6_ext_header_len (p);
 	      p = ip6_ext_next_header (p);
 	    }
 	  l4_proto = p->next_hdr;
 	}
       else
 	l4_proto = ip6->protocol;
       vnet_buffer (b)->l4_hdr_offset = l2hdr_sz + ip6_hdr_len;
     }

   if (l4_proto == IP_PROTOCOL_TCP)
     {
       oflags |= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
       tcp_header_t *tcp = (tcp_header_t *) (vlib_buffer_get_current (b) +
 					    vnet_buffer (b)->l4_hdr_offset);
       *l4_hdr_sz = tcp_header_bytes (tcp);
     }
   else if (l4_proto == IP_PROTOCOL_UDP)
     {
       oflags |= VNET_BUFFER_OFFLOAD_F_UDP_CKSUM;
       *l4_hdr_sz = sizeof (udp_header_t);
     }

   if (oflags)
     vnet_buffer_offload_flags_set (b, oflags);
 }

 always_inline uword
 af_packet_device_input_fn (vlib_main_t *vm, vlib_node_runtime_t *node,
 			   vlib_frame_t *frame, af_packet_if_t *apif,
 			   u16 queue_id, u8 is_cksum_gso_enabled)
 {
   af_packet_main_t *apm = &af_packet_main;
   af_packet_queue_t *rx_queue = vec_elt_at_index (apif->rx_queues, queue_id);
   tpacket3_hdr_t *tph;
   u32 next_index;
   u32 n_free_bufs;
   u32 n_rx_packets = 0;
   u32 n_rx_bytes = 0;
   u32 timedout_blk = 0;
   u32 total = 0;
   u32 *to_next = 0;
   u32 block = rx_queue->next_rx_block;
   u32 block_nr = rx_queue->rx_req->tp_block_nr;
   u8 *block_start = 0;
   uword n_trace = vlib_get_trace_count (vm, node);
   u32 thread_index = vm->thread_index;
   u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm);
   u32 min_bufs = rx_queue->rx_req->tp_frame_size / n_buffer_bytes;
   u32 num_pkts = 0;
   u32 rx_frame_offset = 0;
   block_desc_t *bd = 0;
   vlib_buffer_t bt;
   u8 is_ip = (apif->mode == AF_PACKET_IF_MODE_IP);

   if (is_ip)
     next_index = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
   else
     {
       next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
       if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
 	next_index = apif->per_interface_next_index;

       /* redirect if feature path enabled */
       vnet_feature_start_device_input_x1 (apif->sw_if_index, &next_index, &bt);
     }

   if ((((block_desc_t *) (block_start = rx_queue->rx_ring[block]))
 	 ->hdr.bh1.block_status &
        TP_STATUS_USER) != 0)
     {
       u32 n_required = 0;
       bd = (block_desc_t *) block_start;

       total++;

       if (TP_STATUS_BLK_TMO & bd->hdr.bh1.block_status)
 	timedout_blk++;

       if (PREDICT_FALSE (rx_queue->is_rx_pending))
 	{
 	  num_pkts = rx_queue->num_rx_pkts;
 	  rx_frame_offset = rx_queue->rx_frame_offset;
 	  rx_queue->is_rx_pending = 0;
 	}
       else
 	{
 	  num_pkts = bd->hdr.bh1.num_pkts;
 	  rx_frame_offset = sizeof (block_desc_t);
 	}

       n_required = clib_max (num_pkts, VLIB_FRAME_SIZE);
       n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
       if (PREDICT_FALSE (n_free_bufs < n_required))
 	{
 	  vec_validate (apm->rx_buffers[thread_index],
 			n_required + n_free_bufs - 1);
 	  n_free_bufs += vlib_buffer_alloc (
 	    vm, &apm->rx_buffers[thread_index][n_free_bufs], n_required);
 	  vec_set_len (apm->rx_buffers[thread_index], n_free_bufs);
 	}

       while (num_pkts && (n_free_bufs >= min_bufs))
 	{
 	  u32 next0 = next_index;
 	  u32 n_left_to_next;

 	  vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

 	  while (num_pkts && n_left_to_next && (n_free_bufs >= min_bufs))
 	    {
 	      tph = (tpacket3_hdr_t *) (block_start + rx_frame_offset);

 	      if (num_pkts > 1)
 		CLIB_PREFETCH (block_start + rx_frame_offset +
 				 tph->tp_next_offset,
 			       2 * CLIB_CACHE_LINE_BYTES, LOAD);

 	      vlib_buffer_t *b0 = 0, *first_b0 = 0, *prev_b0 = 0;
 	      vnet_virtio_net_hdr_t *vnet_hdr = 0;
 	      u32 data_len = tph->tp_snaplen;
 	      u32 offset = 0;
 	      u32 bi0 = ~0, first_bi0 = ~0;
 	      u8 l4_hdr_sz = 0;

 	      if (is_cksum_gso_enabled)
 		vnet_hdr =
 		  (vnet_virtio_net_hdr_t *) ((u8 *) tph + tph->tp_mac -
 					     sizeof (vnet_virtio_net_hdr_t));

 	      // save current state and return
 	      if (PREDICT_FALSE (((data_len / n_buffer_bytes) + 1) >
 				 vec_len (apm->rx_buffers[thread_index])))
 		{
 		  rx_queue->rx_frame_offset = rx_frame_offset;
 		  rx_queue->num_rx_pkts = num_pkts;
 		  rx_queue->is_rx_pending = 1;
 		  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 		  goto done;
 		}

 	      while (data_len)
 		{
 		  /* grab free buffer */
 		  u32 last_empty_buffer =
 		    vec_len (apm->rx_buffers[thread_index]) - 1;
 		  bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
 		  vec_set_len (apm->rx_buffers[thread_index],
 			       last_empty_buffer);
 		  n_free_bufs--;

 		  /* copy data */
 		  u32 bytes_to_copy =
 		    data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
 		  u32 vlan_len = 0;
 		  u32 bytes_copied = 0;

 		  b0 = vlib_get_buffer (vm, bi0);
 		  b0->current_data = 0;

 		  /* Kernel removes VLAN headers, so reconstruct VLAN */
 		  if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
 		    {
 		      if (PREDICT_TRUE (offset == 0))
 			{
 			  clib_memcpy_fast (vlib_buffer_get_current (b0),
 					    (u8 *) tph + tph->tp_mac,
 					    sizeof (ethernet_header_t));
 			  ethernet_header_t *eth =
 			    vlib_buffer_get_current (b0);
 			  ethernet_vlan_header_t *vlan =
 			    (ethernet_vlan_header_t *) (eth + 1);
 			  vlan->priority_cfi_and_id =
 			    clib_host_to_net_u16 (tph->hv1.tp_vlan_tci);
 			  vlan->type = eth->type;
 			  eth->type =
 			    clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
 			  vlan_len = sizeof (ethernet_vlan_header_t);
 			  bytes_copied = sizeof (ethernet_header_t);
 			}
 		    }
 		  clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
 				      bytes_copied + vlan_len,
 				    (u8 *) tph + tph->tp_mac + offset +
 				      bytes_copied,
 				    (bytes_to_copy - bytes_copied));

 		  /* fill buffer header */
 		  b0->current_length = bytes_to_copy + vlan_len;

 		  if (offset == 0)
 		    {
 		      b0->total_length_not_including_first_buffer = 0;
 		      b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 		      vnet_buffer (b0)->sw_if_index[VLIB_RX] =
 			apif->sw_if_index;
 		      vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~0;
 		      first_b0 = b0;
 		      first_bi0 = bi0;
 		      if (is_cksum_gso_enabled)
 			{
 			  if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
 			    fill_cksum_offload (first_b0, &l4_hdr_sz, is_ip);
 			  if (vnet_hdr->gso_type & (VIRTIO_NET_HDR_GSO_TCPV4 |
 						    VIRTIO_NET_HDR_GSO_TCPV6))
 			    fill_gso_offload (first_b0, vnet_hdr->gso_size,
 					      l4_hdr_sz);
 			}
 		    }
 		  else
 		    buffer_add_to_chain (b0, first_b0, prev_b0, bi0);

 		  prev_b0 = b0;
 		  offset += bytes_to_copy;
 		  data_len -= bytes_to_copy;
 		}
 	      n_rx_packets++;
 	      n_rx_bytes += tph->tp_snaplen;
 	      to_next[0] = first_bi0;
 	      to_next += 1;
 	      n_left_to_next--;

 	      /* drop partial packets */
 	      if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
 		{
 		  next0 = VNET_DEVICE_INPUT_NEXT_DROP;
 		  first_b0->error =
 		    node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
 		}
 	      else
 		{
 		  if (PREDICT_FALSE (apif->mode == AF_PACKET_IF_MODE_IP))
 		    {
 		      switch (first_b0->data[0] & 0xf0)
 			{
 			case 0x40:
 			  next0 = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
 			  break;
 			case 0x60:
 			  next0 = VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
 			  break;
 			default:
 			  next0 = VNET_DEVICE_INPUT_NEXT_DROP;
 			  break;
 			}
 		      if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
 			next0 = apif->per_interface_next_index;
 		    }
 		  else
 		    {
 		      /* copy feature arc data from template */
 		      first_b0->current_config_index = bt.current_config_index;
 		      vnet_buffer (first_b0)->feature_arc_index =
 			vnet_buffer (&bt)->feature_arc_index;
 		    }
 		}

 	      /* trace */
 	      if (PREDICT_FALSE (n_trace > 0 &&
 				 vlib_trace_buffer (vm, node, next0, first_b0,
 						    /* follow_chain */ 0)))
 		{
 		  af_packet_input_trace_t *tr;
 		  vlib_set_trace_count (vm, node, --n_trace);
 		  tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
 		  tr->next_index = next0;
 		  tr->hw_if_index = apif->hw_if_index;
 		  tr->queue_id = queue_id;
 		  tr->block = block;
 		  tr->block_start = bd;
 		  tr->pkt_num = bd->hdr.bh1.num_pkts - num_pkts;
 		  clib_memcpy_fast (&tr->bd, bd, sizeof (block_desc_t));
 		  clib_memcpy_fast (&tr->tph, tph, sizeof (tpacket3_hdr_t));
 		  if (is_cksum_gso_enabled)
 		    clib_memcpy_fast (&tr->vnet_hdr, vnet_hdr,
 				      sizeof (vnet_virtio_net_hdr_t));
 		  else
 		    clib_memset_u8 (&tr->vnet_hdr, 0,
 				    sizeof (vnet_virtio_net_hdr_t));
 		}

 	      /* enque and take next packet */
 	      vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 					       n_left_to_next, first_bi0,
 					       next0);

 	      /* next packet */
 	      num_pkts--;
 	      rx_frame_offset += tph->tp_next_offset;
 	    }

 	  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 	}

       if (PREDICT_TRUE (num_pkts == 0))
 	{
 	  bd->hdr.bh1.block_status = TP_STATUS_KERNEL;
 	  block = (block + 1) % block_nr;
 	}
       else
 	{
 	  rx_queue->rx_frame_offset = rx_frame_offset;
 	  rx_queue->num_rx_pkts = num_pkts;
 	  rx_queue->is_rx_pending = 1;
 	}
     }

   rx_queue->next_rx_block = block;

 done:

   if ((((block_desc_t *) (block_start = rx_queue->rx_ring[block]))
 	 ->hdr.bh1.block_status &
        TP_STATUS_USER) != 0)
     vlib_node_set_state (vm, node->node_index, VLIB_NODE_STATE_POLLING);
   else
     vlib_node_set_state (vm, node->node_index, VLIB_NODE_STATE_INTERRUPT);

   vlib_error_count (vm, node->node_index, AF_PACKET_INPUT_ERROR_TOTAL_RECV_BLK,
 		    total);
   vlib_error_count (vm, node->node_index, AF_PACKET_INPUT_ERROR_TIMEDOUT_BLK,
 		    timedout_blk);

   vlib_increment_combined_counter
     (vnet_get_main ()->interface_main.combined_sw_if_counters
      + VNET_INTERFACE_COUNTER_RX,
      vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);

   vnet_device_increment_rx_packets (thread_index, n_rx_packets);
   return n_rx_packets;
 }

 VLIB_NODE_FN (af_packet_input_node) (vlib_main_t * vm,
 				     vlib_node_runtime_t * node,
 				     vlib_frame_t * frame)
 {
   u32 n_rx_packets = 0;
   af_packet_main_t *apm = &af_packet_main;
   vnet_hw_if_rxq_poll_vector_t *pv;
   pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
   for (int i = 0; i < vec_len (pv); i++)
     {
       af_packet_if_t *apif;
       apif = vec_elt_at_index (apm->interfaces, pv[i].dev_instance);
       if (apif->is_admin_up)
 	{
 	  if (apif->is_cksum_gso_enabled)
 	    n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif,
 						       pv[i].queue_id, 1);
 	  else
 	    n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif,
 						       pv[i].queue_id, 0);
 	}
     }
   return n_rx_packets;
 }

 VLIB_REGISTER_NODE (af_packet_input_node) = {
   .name = "af-packet-input",
   .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
   .sibling_of = "device-input",
   .format_trace = format_af_packet_input_trace,
   .type = VLIB_NODE_TYPE_INPUT,
   .state = VLIB_NODE_STATE_INTERRUPT,
   .n_errors = AF_PACKET_INPUT_N_ERROR,
   .error_strings = af_packet_input_error_strings,
 };


 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	*------------------------------------------------------------------
	* af_packet.c - linux kernel packet interface
	*
	* 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.
	*------------------------------------------------------------------
	*/

	#include <linux/if_packet.h>

	#include <vlib/vlib.h>
	#include <vlib/unix/unix.h>
	#include <vnet/ip/ip.h>
	#include <vnet/ethernet/ethernet.h>
	#include <vnet/interface/rx_queue_funcs.h>
	#include <vnet/feature/feature.h>
	#include <vnet/ethernet/packet.h>

	#include <vnet/devices/af_packet/af_packet.h>
	#include <vnet/devices/virtio/virtio_std.h>

	#define foreach_af_packet_input_error \
	_ (PARTIAL_PKT, "partial packet") \
	_ (TIMEDOUT_BLK, "timed out block") \
	_ (TOTAL_RECV_BLK, "total received block")
	typedef enum
	{
	#define _(f,s) AF_PACKET_INPUT_ERROR_##f,
	foreach_af_packet_input_error
	#undef _
	AF_PACKET_INPUT_N_ERROR,
	} af_packet_input_error_t;

	static char *af_packet_input_error_strings[] = {
	#define _(n,s) s,
	foreach_af_packet_input_error
	#undef _
	};

	typedef struct
	{
	u32 next_index;
	u32 hw_if_index;
	u16 queue_id;
	int block;
	u32 pkt_num;
	void *block_start;
	block_desc_t bd;
	tpacket3_hdr_t tph;
	vnet_virtio_net_hdr_t vnet_hdr;
	} af_packet_input_trace_t;

	static u8 *
	format_af_packet_input_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 );
	af_packet_input_trace_t t = va_arg (args, af_packet_input_trace_t *);
	u32 indent = format_get_indent (s);

	s = format (s, "af_packet: hw_if_index %d rx-queue %u next-index %d",
	t->hw_if_index, t->queue_id, t->next_index);

	s = format (
	s, "\n%Ublock %u:\n%Uaddress %p version %u seq_num %lu pkt_num %u",
	format_white_space, indent + 2, t->block, format_white_space, indent + 4,
	t->block_start, t->bd.version, t->bd.hdr.bh1.seq_num, t->pkt_num);
	s =
	format (s,
	"\n%Utpacket3_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
	"\n%Usec 0x%x nsec 0x%x vlan %U"
	#ifdef TP_STATUS_VLAN_TPID_VALID
	" vlan_tpid %u"
	#endif
	,
	format_white_space, indent + 2, format_white_space, indent + 4,
	t->tph.tp_status, t->tph.tp_len, t->tph.tp_snaplen, t->tph.tp_mac,
	t->tph.tp_net, format_white_space, indent + 4, t->tph.tp_sec,
	t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.hv1.tp_vlan_tci
	#ifdef TP_STATUS_VLAN_TPID_VALID
	,
	t->tph.hv1.tp_vlan_tpid
	#endif
	);

	s = format (s,
	"\n%Uvnet-hdr:\n%Uflags 0x%02x gso_type 0x%02x hdr_len %u"
	"\n%Ugso_size %u csum_start %u csum_offset %u",
	format_white_space, indent + 2, format_white_space, indent + 4,
	t->vnet_hdr.flags, t->vnet_hdr.gso_type, t->vnet_hdr.hdr_len,
	format_white_space, indent + 4, t->vnet_hdr.gso_size,
	t->vnet_hdr.csum_start, t->vnet_hdr.csum_offset);
	return s;
	}

	always_inline void
	buffer_add_to_chain (vlib_buffer_t b, vlib_buffer_t first_b,
	vlib_buffer_t *prev_b, u32 bi)
	{
	/* update first buffer */
	first_b->total_length_not_including_first_buffer += b->current_length;

	/* update previous buffer */
	prev_b->next_buffer = bi;
	prev_b->flags \|= VLIB_BUFFER_NEXT_PRESENT;

	/* update current buffer */
	b->next_buffer = ~0;
	}

	static_always_inline void
	fill_gso_offload (vlib_buffer_t *b, u32 gso_size, u8 l4_hdr_sz)
	{
	b->flags \|= VNET_BUFFER_F_GSO;
	vnet_buffer2 (b)->gso_size = gso_size;
	vnet_buffer2 (b)->gso_l4_hdr_sz = l4_hdr_sz;
	}

	static_always_inline void
	fill_cksum_offload (vlib_buffer_t b, u8 l4_hdr_sz, u8 is_ip)
	{
	vnet_buffer_oflags_t oflags = 0;
	u16 l2hdr_sz = 0;
	u16 ethertype = 0;
	u8 l4_proto = 0;

	if (is_ip)
	{
	switch (b->data[0] & 0xf0)
	{
	case 0x40:
	ethertype = ETHERNET_TYPE_IP4;
	break;
	case 0x60:
	ethertype = ETHERNET_TYPE_IP6;
	break;
	}
	}
	else
	{
	ethernet_header_t *eth = vlib_buffer_get_current (b);
	ethertype = clib_net_to_host_u16 (eth->type);
	l2hdr_sz = sizeof (ethernet_header_t);
	if (ethernet_frame_is_tagged (ethertype))
	{
	ethernet_vlan_header_t vlan = (ethernet_vlan_header_t ) (eth + 1);

	ethertype = clib_net_to_host_u16 (vlan->type);
	l2hdr_sz += sizeof (*vlan);
	if (ethertype == ETHERNET_TYPE_VLAN)
	{
	vlan++;
	ethertype = clib_net_to_host_u16 (vlan->type);
	l2hdr_sz += sizeof (*vlan);
	}
	}
	}

	vnet_buffer (b)->l2_hdr_offset = 0;
	vnet_buffer (b)->l3_hdr_offset = l2hdr_sz;

	if (ethertype == ETHERNET_TYPE_IP4)
	{
	ip4_header_t *ip4 = (vlib_buffer_get_current (b) + l2hdr_sz);
	vnet_buffer (b)->l4_hdr_offset = l2hdr_sz + ip4_header_bytes (ip4);
	b->flags \|= (VNET_BUFFER_F_IS_IP4 \| VNET_BUFFER_F_L2_HDR_OFFSET_VALID \|
	VNET_BUFFER_F_L3_HDR_OFFSET_VALID \|
	VNET_BUFFER_F_L4_HDR_OFFSET_VALID);

	l4_proto = ip4->protocol;
	}
	else if (ethertype == ETHERNET_TYPE_IP6)
	{
	ip6_header_t *ip6 = (vlib_buffer_get_current (b) + l2hdr_sz);
	b->flags \|= (VNET_BUFFER_F_IS_IP6 \| VNET_BUFFER_F_L2_HDR_OFFSET_VALID \|
	VNET_BUFFER_F_L3_HDR_OFFSET_VALID \|
	VNET_BUFFER_F_L4_HDR_OFFSET_VALID);
	u16 ip6_hdr_len = sizeof (ip6_header_t);

	if (ip6_ext_hdr (ip6->protocol))
	{
	ip6_ext_header_t p = (void ) (ip6 + 1);
	ip6_hdr_len += ip6_ext_header_len (p);
	while (ip6_ext_hdr (p->next_hdr))
	{
	ip6_hdr_len += ip6_ext_header_len (p);
	p = ip6_ext_next_header (p);
	}
	l4_proto = p->next_hdr;
	}
	else
	l4_proto = ip6->protocol;
	vnet_buffer (b)->l4_hdr_offset = l2hdr_sz + ip6_hdr_len;
	}

	if (l4_proto == IP_PROTOCOL_TCP)
	{
	oflags \|= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
	tcp_header_t tcp = (tcp_header_t ) (vlib_buffer_get_current (b) +
	vnet_buffer (b)->l4_hdr_offset);
	*l4_hdr_sz = tcp_header_bytes (tcp);
	}
	else if (l4_proto == IP_PROTOCOL_UDP)
	{
	oflags \|= VNET_BUFFER_OFFLOAD_F_UDP_CKSUM;
	*l4_hdr_sz = sizeof (udp_header_t);
	}

	if (oflags)
	vnet_buffer_offload_flags_set (b, oflags);
	}

	always_inline uword
	af_packet_device_input_fn (vlib_main_t vm, vlib_node_runtime_t node,
	vlib_frame_t frame, af_packet_if_t apif,
	u16 queue_id, u8 is_cksum_gso_enabled)
	{
	af_packet_main_t *apm = &af_packet_main;
	af_packet_queue_t *rx_queue = vec_elt_at_index (apif->rx_queues, queue_id);
	tpacket3_hdr_t *tph;
	u32 next_index;
	u32 n_free_bufs;
	u32 n_rx_packets = 0;
	u32 n_rx_bytes = 0;
	u32 timedout_blk = 0;
	u32 total = 0;
	u32 *to_next = 0;
	u32 block = rx_queue->next_rx_block;
	u32 block_nr = rx_queue->rx_req->tp_block_nr;
	u8 *block_start = 0;
	uword n_trace = vlib_get_trace_count (vm, node);
	u32 thread_index = vm->thread_index;
	u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm);
	u32 min_bufs = rx_queue->rx_req->tp_frame_size / n_buffer_bytes;
	u32 num_pkts = 0;
	u32 rx_frame_offset = 0;
	block_desc_t *bd = 0;
	vlib_buffer_t bt;
	u8 is_ip = (apif->mode == AF_PACKET_IF_MODE_IP);

	if (is_ip)
	next_index = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
	else
	{
	next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
	if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
	next_index = apif->per_interface_next_index;

	/* redirect if feature path enabled */
	vnet_feature_start_device_input_x1 (apif->sw_if_index, &next_index, &bt);
	}

	if ((((block_desc_t *) (block_start = rx_queue->rx_ring[block]))
	->hdr.bh1.block_status &
	TP_STATUS_USER) != 0)
	{
	u32 n_required = 0;
	bd = (block_desc_t *) block_start;

	total++;

	if (TP_STATUS_BLK_TMO & bd->hdr.bh1.block_status)
	timedout_blk++;

	if (PREDICT_FALSE (rx_queue->is_rx_pending))
	{
	num_pkts = rx_queue->num_rx_pkts;
	rx_frame_offset = rx_queue->rx_frame_offset;
	rx_queue->is_rx_pending = 0;
	}
	else
	{
	num_pkts = bd->hdr.bh1.num_pkts;
	rx_frame_offset = sizeof (block_desc_t);
	}

	n_required = clib_max (num_pkts, VLIB_FRAME_SIZE);
	n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
	if (PREDICT_FALSE (n_free_bufs < n_required))
	{
	vec_validate (apm->rx_buffers[thread_index],
	n_required + n_free_bufs - 1);
	n_free_bufs += vlib_buffer_alloc (
	vm, &apm->rx_buffers[thread_index][n_free_bufs], n_required);
	vec_set_len (apm->rx_buffers[thread_index], n_free_bufs);
	}

	while (num_pkts && (n_free_bufs >= min_bufs))
	{
	u32 next0 = next_index;
	u32 n_left_to_next;

	vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

	while (num_pkts && n_left_to_next && (n_free_bufs >= min_bufs))
	{
	tph = (tpacket3_hdr_t *) (block_start + rx_frame_offset);

	if (num_pkts > 1)
	CLIB_PREFETCH (block_start + rx_frame_offset +
	tph->tp_next_offset,
	2 * CLIB_CACHE_LINE_BYTES, LOAD);

	vlib_buffer_t b0 = 0, first_b0 = 0, *prev_b0 = 0;
	vnet_virtio_net_hdr_t *vnet_hdr = 0;
	u32 data_len = tph->tp_snaplen;
	u32 offset = 0;
	u32 bi0 = ~0, first_bi0 = ~0;
	u8 l4_hdr_sz = 0;

	if (is_cksum_gso_enabled)
	vnet_hdr =
	(vnet_virtio_net_hdr_t ) ((u8 ) tph + tph->tp_mac -
	sizeof (vnet_virtio_net_hdr_t));

	// save current state and return
	if (PREDICT_FALSE (((data_len / n_buffer_bytes) + 1) >
	vec_len (apm->rx_buffers[thread_index])))
	{
	rx_queue->rx_frame_offset = rx_frame_offset;
	rx_queue->num_rx_pkts = num_pkts;
	rx_queue->is_rx_pending = 1;
	vlib_put_next_frame (vm, node, next_index, n_left_to_next);
	goto done;
	}

	while (data_len)
	{
	/* grab free buffer */
	u32 last_empty_buffer =
	vec_len (apm->rx_buffers[thread_index]) - 1;
	bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
	vec_set_len (apm->rx_buffers[thread_index],
	last_empty_buffer);
	n_free_bufs--;

	/* copy data */
	u32 bytes_to_copy =
	data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
	u32 vlan_len = 0;
	u32 bytes_copied = 0;

	b0 = vlib_get_buffer (vm, bi0);
	b0->current_data = 0;

	/* Kernel removes VLAN headers, so reconstruct VLAN */
	if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
	{
	if (PREDICT_TRUE (offset == 0))
	{
	clib_memcpy_fast (vlib_buffer_get_current (b0),
	(u8 *) tph + tph->tp_mac,
	sizeof (ethernet_header_t));
	ethernet_header_t *eth =
	vlib_buffer_get_current (b0);
	ethernet_vlan_header_t *vlan =
	(ethernet_vlan_header_t *) (eth + 1);
	vlan->priority_cfi_and_id =
	clib_host_to_net_u16 (tph->hv1.tp_vlan_tci);
	vlan->type = eth->type;
	eth->type =
	clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
	vlan_len = sizeof (ethernet_vlan_header_t);
	bytes_copied = sizeof (ethernet_header_t);
	}
	}
	clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
	bytes_copied + vlan_len,
	(u8 *) tph + tph->tp_mac + offset +
	bytes_copied,
	(bytes_to_copy - bytes_copied));

	/* fill buffer header */
	b0->current_length = bytes_to_copy + vlan_len;

	if (offset == 0)
	{
	b0->total_length_not_including_first_buffer = 0;
	b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
	vnet_buffer (b0)->sw_if_index[VLIB_RX] =
	apif->sw_if_index;
	vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~0;
	first_b0 = b0;
	first_bi0 = bi0;
	if (is_cksum_gso_enabled)
	{
	if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
	fill_cksum_offload (first_b0, &l4_hdr_sz, is_ip);
	if (vnet_hdr->gso_type & (VIRTIO_NET_HDR_GSO_TCPV4 \|
	VIRTIO_NET_HDR_GSO_TCPV6))
	fill_gso_offload (first_b0, vnet_hdr->gso_size,
	l4_hdr_sz);
	}
	}
	else
	buffer_add_to_chain (b0, first_b0, prev_b0, bi0);

	prev_b0 = b0;
	offset += bytes_to_copy;
	data_len -= bytes_to_copy;
	}
	n_rx_packets++;
	n_rx_bytes += tph->tp_snaplen;
	to_next[0] = first_bi0;
	to_next += 1;
	n_left_to_next--;

	/* drop partial packets */
	if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
	{
	next0 = VNET_DEVICE_INPUT_NEXT_DROP;
	first_b0->error =
	node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
	}
	else
	{
	if (PREDICT_FALSE (apif->mode == AF_PACKET_IF_MODE_IP))
	{
	switch (first_b0->data[0] & 0xf0)
	{
	case 0x40:
	next0 = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
	break;
	case 0x60:
	next0 = VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
	break;
	default:
	next0 = VNET_DEVICE_INPUT_NEXT_DROP;
	break;
	}
	if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
	next0 = apif->per_interface_next_index;
	}
	else
	{
	/* copy feature arc data from template */
	first_b0->current_config_index = bt.current_config_index;
	vnet_buffer (first_b0)->feature_arc_index =
	vnet_buffer (&bt)->feature_arc_index;
	}
	}

	/* trace */
	if (PREDICT_FALSE (n_trace > 0 &&
	vlib_trace_buffer (vm, node, next0, first_b0,
	/* follow_chain */ 0)))
	{
	af_packet_input_trace_t *tr;
	vlib_set_trace_count (vm, node, --n_trace);
	tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
	tr->next_index = next0;
	tr->hw_if_index = apif->hw_if_index;
	tr->queue_id = queue_id;
	tr->block = block;
	tr->block_start = bd;
	tr->pkt_num = bd->hdr.bh1.num_pkts - num_pkts;
	clib_memcpy_fast (&tr->bd, bd, sizeof (block_desc_t));
	clib_memcpy_fast (&tr->tph, tph, sizeof (tpacket3_hdr_t));
	if (is_cksum_gso_enabled)
	clib_memcpy_fast (&tr->vnet_hdr, vnet_hdr,
	sizeof (vnet_virtio_net_hdr_t));
	else
	clib_memset_u8 (&tr->vnet_hdr, 0,
	sizeof (vnet_virtio_net_hdr_t));
	}

	/* enque and take next packet */
	vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
	n_left_to_next, first_bi0,
	next0);

	/* next packet */
	num_pkts--;
	rx_frame_offset += tph->tp_next_offset;
	}

	vlib_put_next_frame (vm, node, next_index, n_left_to_next);
	}

	if (PREDICT_TRUE (num_pkts == 0))
	{
	bd->hdr.bh1.block_status = TP_STATUS_KERNEL;
	block = (block + 1) % block_nr;
	}
	else
	{
	rx_queue->rx_frame_offset = rx_frame_offset;
	rx_queue->num_rx_pkts = num_pkts;
	rx_queue->is_rx_pending = 1;
	}
	}

	rx_queue->next_rx_block = block;

	done:

	if ((((block_desc_t *) (block_start = rx_queue->rx_ring[block]))
	->hdr.bh1.block_status &
	TP_STATUS_USER) != 0)
	vlib_node_set_state (vm, node->node_index, VLIB_NODE_STATE_POLLING);
	else
	vlib_node_set_state (vm, node->node_index, VLIB_NODE_STATE_INTERRUPT);

	vlib_error_count (vm, node->node_index, AF_PACKET_INPUT_ERROR_TOTAL_RECV_BLK,
	total);
	vlib_error_count (vm, node->node_index, AF_PACKET_INPUT_ERROR_TIMEDOUT_BLK,
	timedout_blk);

	vlib_increment_combined_counter
	(vnet_get_main ()->interface_main.combined_sw_if_counters
	+ VNET_INTERFACE_COUNTER_RX,
	vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);

	vnet_device_increment_rx_packets (thread_index, n_rx_packets);
	return n_rx_packets;
	}

	VLIB_NODE_FN (af_packet_input_node) (vlib_main_t * vm,
	vlib_node_runtime_t * node,
	vlib_frame_t * frame)
	{
	u32 n_rx_packets = 0;
	af_packet_main_t *apm = &af_packet_main;
	vnet_hw_if_rxq_poll_vector_t *pv;
	pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
	for (int i = 0; i < vec_len (pv); i++)
	{
	af_packet_if_t *apif;
	apif = vec_elt_at_index (apm->interfaces, pv[i].dev_instance);
	if (apif->is_admin_up)
	{
	if (apif->is_cksum_gso_enabled)
	n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif,
	pv[i].queue_id, 1);
	else
	n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif,
	pv[i].queue_id, 0);
	}
	}
	return n_rx_packets;
	}

	VLIB_REGISTER_NODE (af_packet_input_node) = {
	.name = "af-packet-input",
	.flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
	.sibling_of = "device-input",
	.format_trace = format_af_packet_input_trace,
	.type = VLIB_NODE_TYPE_INPUT,
	.state = VLIB_NODE_STATE_INTERRUPT,
	.n_errors = AF_PACKET_INPUT_N_ERROR,
	.error_strings = af_packet_input_error_strings,
	};


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