Add vpp native linux kernel AF_PACKET interface support

This is 1st drop of VPP native driver for linux AF_PACKET.

New CLI:

  create host-interface name <host-if-name>  [hw-addr <mac-address>]

References:
 - Documentation/networking/packet_mmap.txt in the Linux kernel tree
 - man 7 packet

Known issues:
 - attaching to linux bridge doesn't work
 - it is not expected to work in multicore setup

Change-Id: I1cb1c3d305f349759e90e76e25696718b73bd73d
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 279 insertions, 0 deletions

diff --git a/vnet/vnet/devices/af_packet/node.c b/vnet/vnet/devices/af_packet/node.c
new file mode 100644
index 00000000000..eadb59238a7
--- /dev/null
+++ b/vnet/vnet/devices/af_packet/node.c
@@ -0,0 +1,279 @@
+/*
+ *------------------------------------------------------------------
+ * 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/devices/af_packet/af_packet.h>
+
+#define foreach_af_packet_input_error
+
+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 _
+};
+
+enum {
+  AF_PACKET_INPUT_NEXT_DROP,
+  AF_PACKET_INPUT_NEXT_ETHERNET_INPUT,
+  AF_PACKET_INPUT_N_NEXT,
+};
+
+typedef struct {
+  u32 next_index;
+  u32 hw_if_index;
+  int block;
+  struct tpacket2_hdr tph;
+} 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 *);
+  uword indent = format_get_indent (s);
+
+  s = format (s, "af_packet: hw_if_index %d next-index %d",
+	      t->hw_if_index, t->next_index);
+
+  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_tci %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,
+	      t->tph.tp_vlan_tci,
+#ifdef TP_STATUS_VLAN_TPID_VALID
+	      t->tph.tp_vlan_tpid,
+#endif
+	      t->tph.tp_net);
+  return s;
+}
+
+always_inline void
+buffer_add_to_chain(vlib_main_t *vm, u32 bi, u32 first_bi, u32 prev_bi)
+{
+  vlib_buffer_t * b = vlib_get_buffer (vm, bi);
+  vlib_buffer_t * first_b = vlib_get_buffer (vm, first_bi);
+  vlib_buffer_t * prev_b = vlib_get_buffer (vm, prev_bi);
+#if DPDK > 0
+  struct rte_mbuf * mbuf = ((struct rte_mbuf *) b) - 1;
+  struct rte_mbuf * first_mbuf = ((struct rte_mbuf *) first_b) - 1;
+  struct rte_mbuf * prev_mbuf = ((struct rte_mbuf *) prev_b) - 1;
+#endif
+
+  /* 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;
+
+#if DPDK > 0
+  first_mbuf->nb_segs++;
+  prev_mbuf->next = mbuf;
+  mbuf->data_len = b->current_length;
+  mbuf->data_off = RTE_PKTMBUF_HEADROOM + b->current_data;
+  mbuf->next = 0;
+#endif
+}
+
+always_inline uword
+af_packet_device_input_fn  (vlib_main_t * vm, vlib_node_runtime_t * node,
+			    vlib_frame_t * frame, u32 device_idx)
+{
+  af_packet_main_t * apm = &af_packet_main;
+  af_packet_if_t * apif = vec_elt_at_index(apm->interfaces, device_idx);
+  struct tpacket2_hdr *tph;
+  u32 next_index = AF_PACKET_INPUT_NEXT_ETHERNET_INPUT;
+  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 block_size = apif->rx_req->tp_block_size;
+  u32 frame_size = apif->rx_req->tp_frame_size;
+  u32 frame_num = apif->rx_req->tp_frame_nr;
+  u8 * block_start = apif->rx_ring + block * block_size;
+  uword n_trace = vlib_get_trace_count (vm, node);
+  u32 n_buffer_bytes = vlib_buffer_free_list_buffer_size (vm,
+    VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
+  u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
+
+  n_free_bufs = vec_len (apm->rx_buffers);
+  if (PREDICT_FALSE(n_free_bufs < VLIB_FRAME_SIZE))
+    {
+      vec_validate(apm->rx_buffers, VLIB_FRAME_SIZE + n_free_bufs - 1);
+      n_free_bufs += vlib_buffer_alloc(vm, &apm->rx_buffers[n_free_bufs], VLIB_FRAME_SIZE);
+      _vec_len (apm->rx_buffers) = n_free_bufs;
+    }
+
+  rx_frame = apif->next_rx_frame;
+  tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
+  while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
+    {
+      vlib_buffer_t * b0, * first_b0 = 0;
+      u32 next0 = AF_PACKET_INPUT_NEXT_ETHERNET_INPUT;
+
+      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)
+	{
+	  u32 data_len = tph->tp_snaplen;
+	  u32 offset = 0;
+	  u32 bi0, first_bi0 = 0, prev_bi0;
+
+	  while (data_len)
+	    {
+	      /* grab free buffer */
+	      u32 last_empty_buffer = vec_len (apm->rx_buffers) - 1;
+	      prev_bi0 = bi0;
+	      bi0 = apm->rx_buffers[last_empty_buffer];
+	      b0 = vlib_get_buffer (vm, bi0);
+	      _vec_len (apm->rx_buffers) = last_empty_buffer;
+	      n_free_bufs--;
+
+	      /* copy data */
+	      u32 bytes_to_copy = data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
+	      b0->current_data = 0;
+	      memcpy (vlib_buffer_get_current (b0), (u8 *) tph + tph->tp_mac + offset, bytes_to_copy);
+
+	      /* fill buffer header */
+	      b0->clone_count = 0;
+	      b0->current_length = bytes_to_copy;
+
+	      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);
+		}
+	      else
+		buffer_add_to_chain(vm, bi0, first_bi0, prev_bi0);
+
+	      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--;
+
+	  /* trace */
+	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT(first_b0);
+	  if (PREDICT_FALSE(n_trace > 0))
+	    {
+	      af_packet_input_trace_t *tr;
+	      vlib_trace_buffer (vm, node, next0, first_b0, /* follow_chain */ 0);
+	      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;
+	      memcpy(&tr->tph, tph, sizeof(struct tpacket2_hdr));
+	    }
+	  /* 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);
+    }
+
+  apif->next_rx_frame = rx_frame;
+
+  vlib_increment_combined_counter
+    (vnet_get_main()->interface_main.combined_sw_if_counters
+     + VNET_INTERFACE_COUNTER_RX,
+     os_get_cpu_number(),
+     apif->hw_if_index,
+     n_rx_packets, n_rx_bytes);
+
+  return n_rx_packets;
+}
+
+static uword
+af_packet_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+		    vlib_frame_t * frame)
+{
+  int i;
+  u32 n_rx_packets = 0;
+
+  af_packet_main_t * apm = &af_packet_main;
+
+  clib_bitmap_foreach (i, apm->pending_input_bitmap,
+    ({
+      clib_bitmap_set (apm->pending_input_bitmap, i, 1);
+      n_rx_packets += af_packet_device_input_fn(vm, node, frame, i);
+    }));
+
+  return n_rx_packets;
+}
+
+
+VLIB_REGISTER_NODE (af_packet_input_node) = {
+  .function = af_packet_input_fn,
+  .name = "af-packet-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,
+
+  .n_next_nodes = AF_PACKET_INPUT_N_NEXT,
+  .next_nodes = {
+    [AF_PACKET_INPUT_NEXT_DROP] = "error-drop",
+    [AF_PACKET_INPUT_NEXT_ETHERNET_INPUT] = "ethernet-input",
+  },
+};