af_packet: move to plugin

Type: improvement

Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
Change-Id: I3ec857adb3a9e8a778072a202a4d23f4101e83b2

1 files changed, 845 insertions, 0 deletions

diff --git a/src/plugins/af_packet/node.c b/src/plugins/af_packet/node.c
new file mode 100644
index 00000000000..0ea4b3dfea7
--- /dev/null
+++ b/src/plugins/af_packet/node.c
@@ -0,0 +1,845 @@
+/*
+ *------------------------------------------------------------------
+ * 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 <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;
+  union
+  {
+    tpacket3_hdr_t tph3;
+    tpacket2_hdr_t tph2;
+  };
+  vnet_virtio_net_hdr_t vnet_hdr;
+  u8 is_v3;
+} 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);
+
+  if (t->is_v3)
+    {
+      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->tph3.tp_status, t->tph3.tp_len, t->tph3.tp_snaplen, t->tph3.tp_mac,
+	t->tph3.tp_net, format_white_space, indent + 4, t->tph3.tp_sec,
+	t->tph3.tp_nsec, format_ethernet_vlan_tci, t->tph3.hv1.tp_vlan_tci
+#ifdef TP_STATUS_VLAN_TPID_VALID
+	,
+	t->tph3.hv1.tp_vlan_tpid
+#endif
+      );
+    }
+  else
+    {
+      s = format (
+	s,
+	"\n%Utpacket2_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->tph2.tp_status, t->tph2.tp_len, t->tph2.tp_snaplen, t->tph2.tp_mac,
+	t->tph2.tp_net, format_white_space, indent + 4, t->tph2.tp_sec,
+	t->tph2.tp_nsec, format_ethernet_vlan_tci, t->tph2.tp_vlan_tci
+#ifdef TP_STATUS_VLAN_TPID_VALID
+	,
+	t->tph2.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 = (ethernet_header_t *) b->data;
+      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 = (ip4_header_t *) (b->data + 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 = (ip6_header_t *) (b->data + 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 *) (b->data + 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_v3_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->req3.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->req3.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;
+
+      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);
+	  total++;
+
+	  if (TP_STATUS_BLK_TMO & bd->hdr.bh1.block_status)
+	    timedout_blk++;
+	}
+
+      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->is_v3 = 1;
+		  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->tph3, 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 (apm->polling_count == 0)
+    {
+      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;
+}
+
+always_inline uword
+af_packet_v2_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);
+  tpacket2_hdr_t *tph;
+  u32 next_index;
+  u32 block = 0;
+  u32 rx_frame;
+  u32 n_free_bufs;
+  u32 n_rx_packets = 0;
+  u32 n_rx_bytes = 0;
+  u32 *to_next = 0;
+  u32 frame_size = rx_queue->rx_req->req.tp_frame_size;
+  u32 frame_num = rx_queue->rx_req->req.tp_frame_nr;
+  u8 *block_start = rx_queue->rx_ring[block];
+  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->req.tp_frame_size / n_buffer_bytes;
+  u8 is_ip = (apif->mode == AF_PACKET_IF_MODE_IP);
+  vlib_buffer_t bt = {};
+
+  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);
+    }
+
+  n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
+  if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
+    {
+      vec_validate (apm->rx_buffers[thread_index],
+		    VLIB_FRAME_SIZE + n_free_bufs - 1);
+      n_free_bufs += vlib_buffer_alloc (
+	vm, &apm->rx_buffers[thread_index][n_free_bufs], VLIB_FRAME_SIZE);
+      vec_set_len (apm->rx_buffers[thread_index], n_free_bufs);
+    }
+
+  rx_frame = rx_queue->next_rx_frame;
+  tph = (tpacket2_hdr_t *) (block_start + rx_frame * frame_size);
+  while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
+    {
+      vlib_buffer_t *b0 = 0, *first_b0 = 0, *prev_b0 = 0;
+      u32 next0 = next_index;
+
+      u32 n_left_to_next;
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+      while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
+	     n_left_to_next)
+	{
+	  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));
+	  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];
+	      b0 = vlib_get_buffer (vm, bi0);
+	      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->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->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_bi0 = bi0;
+		  first_b0 = vlib_get_buffer (vm, first_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 (is_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->is_v3 = 0;
+	      tr->next_index = next0;
+	      tr->hw_if_index = apif->hw_if_index;
+	      tr->queue_id = queue_id;
+	      clib_memcpy_fast (&tr->tph2, tph, sizeof (struct tpacket2_hdr));
+	      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 */
+	  tph->tp_status = TP_STATUS_KERNEL;
+	  rx_frame = (rx_frame + 1) % frame_num;
+	  tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  rx_queue->next_rx_frame = rx_frame;
+
+  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;
+}
+
+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)
+
+{
+  if (apif->version == TPACKET_V3)
+    return af_packet_v3_device_input_fn (vm, node, frame, apif, queue_id,
+					 is_cksum_gso_enabled);
+  else
+    return af_packet_v2_device_input_fn (vm, node, frame, apif, queue_id,
+					 is_cksum_gso_enabled);
+}
+
+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:
+ */