netmap: Reinstate and update netmap plugin

Thet netmap plugin was moved to depreciated in commit 998b8fe.

On FreeBSD netmap offers a natively supported kernel interface for
userspace networking and enables VPP without the use of DPDK.

Reinstate the netmap plugin and adapt it to the newer plugin interface.

Type: improvement
Change-Id: I113daa33a490f04cbb29909f9789fa66284ac80e
Signed-off-by: Tom Jones <thj@freebsd.org>

1 files changed, 295 insertions, 0 deletions

diff --git a/src/plugins/netmap/node.c b/src/plugins/netmap/node.c
new file mode 100644
index 00000000000..6169847fa79
--- /dev/null
+++ b/src/plugins/netmap/node.c
@@ -0,0 +1,295 @@
+/*
+ *------------------------------------------------------------------
+ * 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 <stdint.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/devices/devices.h>
+#include <vnet/feature/feature.h>
+
+#include <netmap/net_netmap.h>
+#include <netmap/netmap.h>
+
+#define foreach_netmap_input_error
+
+typedef enum
+{
+#define _(f,s) NETMAP_INPUT_ERROR_##f,
+  foreach_netmap_input_error
+#undef _
+    NETMAP_INPUT_N_ERROR,
+} netmap_input_error_t;
+
+static char *netmap_input_error_strings[] = {
+#define _(n,s) s,
+  foreach_netmap_input_error
+#undef _
+};
+
+typedef struct
+{
+  u32 next_index;
+  u32 hw_if_index;
+  struct netmap_slot slot;
+} netmap_input_trace_t;
+
+static u8 *
+format_netmap_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 *);
+  netmap_input_trace_t *t = va_arg (*args, netmap_input_trace_t *);
+  u32 indent = format_get_indent (s);
+
+  s = format (s, "netmap: hw_if_index %d next-index %d",
+	      t->hw_if_index, t->next_index);
+  s = format (s, "\n%Uslot: flags 0x%x len %u buf_idx %u",
+	      format_white_space, indent + 2,
+	      t->slot.flags, t->slot.len, t->slot.buf_idx);
+  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);
+
+  /* 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;
+}
+
+always_inline uword
+netmap_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+			vlib_frame_t * frame, netmap_if_t * nif)
+{
+  u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+  uword n_trace = vlib_get_trace_count (vm, node);
+  netmap_main_t *nm = &netmap_main;
+  u32 n_rx_packets = 0;
+  u32 n_rx_bytes = 0;
+  u32 *to_next = 0;
+  u32 n_free_bufs;
+  struct netmap_ring *ring;
+  int cur_ring;
+  u32 thread_index = vm->thread_index;
+  u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm);
+
+  if (nif->per_interface_next_index != ~0)
+    next_index = nif->per_interface_next_index;
+
+  n_free_bufs = vec_len (nm->rx_buffers[thread_index]);
+  if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
+    {
+      vec_validate (nm->rx_buffers[thread_index],
+		    VLIB_FRAME_SIZE + n_free_bufs - 1);
+      n_free_bufs +=
+	vlib_buffer_alloc (vm, &nm->rx_buffers[thread_index][n_free_bufs],
+			   VLIB_FRAME_SIZE);
+      vec_set_len (nm->rx_buffers[thread_index], n_free_bufs);
+    }
+
+  cur_ring = nif->first_rx_ring;
+  while (cur_ring <= nif->last_rx_ring && n_free_bufs)
+    {
+      int r = 0;
+      u32 cur_slot_index;
+      ring = NETMAP_RXRING (nif->nifp, cur_ring);
+      r = nm_ring_space (ring);
+
+      if (!r)
+	{
+	  cur_ring++;
+	  continue;
+	}
+
+      if (r > n_free_bufs)
+	r = n_free_bufs;
+
+      cur_slot_index = ring->cur;
+      while (r)
+	{
+	  u32 n_left_to_next;
+	  u32 next0 = next_index;
+	  vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+	  while (r && n_left_to_next)
+	    {
+	      vlib_buffer_t *first_b0 = 0;
+	      u32 offset = 0;
+	      u32 bi0 = 0, first_bi0 = 0, prev_bi0;
+	      u32 next_slot_index = (cur_slot_index + 1) % ring->num_slots;
+	      u32 next2_slot_index = (cur_slot_index + 2) % ring->num_slots;
+	      struct netmap_slot *slot = &ring->slot[cur_slot_index];
+	      u32 data_len = slot->len;
+
+	      /* prefetch 2 slots in advance */
+	      CLIB_PREFETCH (&ring->slot[next2_slot_index],
+			     CLIB_CACHE_LINE_BYTES, LOAD);
+	      /* prefetch start of next packet */
+	      CLIB_PREFETCH (NETMAP_BUF
+			     (ring, ring->slot[next_slot_index].buf_idx),
+			     CLIB_CACHE_LINE_BYTES, LOAD);
+
+	      while (data_len && n_free_bufs)
+		{
+		  vlib_buffer_t *b0;
+		  /* grab free buffer */
+		  u32 last_empty_buffer =
+		    vec_len (nm->rx_buffers[thread_index]) - 1;
+		  prev_bi0 = bi0;
+		  bi0 = nm->rx_buffers[thread_index][last_empty_buffer];
+		  b0 = vlib_get_buffer (vm, bi0);
+		  vec_set_len (nm->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;
+		  b0->current_data = 0;
+		  clib_memcpy_fast (vlib_buffer_get_current (b0),
+				    (u8 *) NETMAP_BUF (ring, slot->buf_idx) +
+				    offset, bytes_to_copy);
+
+		  /* fill buffer header */
+		  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] =
+			nif->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;
+		}
+
+	      /* trace */
+	      if (PREDICT_FALSE (n_trace > 0))
+		{
+		  if (PREDICT_TRUE (first_b0 != 0) &&
+		      vlib_trace_buffer (vm, node, next0, first_b0,
+					 /* follow_chain */ 0))
+		    {
+		      netmap_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 = nif->hw_if_index;
+		      memcpy (&tr->slot, slot, sizeof (struct netmap_slot));
+		    }
+		}
+
+	      /* 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 */
+	      n_rx_packets++;
+	      n_rx_bytes += slot->len;
+	      to_next[0] = first_bi0;
+	      to_next += 1;
+	      n_left_to_next--;
+	      cur_slot_index = next_slot_index;
+
+	      r--;
+	    }
+	  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+	}
+      ring->head = ring->cur = cur_slot_index;
+      cur_ring++;
+    }
+
+  if (n_rx_packets)
+    ioctl (nif->fd, NIOCRXSYNC, NULL);
+
+  vlib_increment_combined_counter
+    (vnet_get_main ()->interface_main.combined_sw_if_counters
+     + VNET_INTERFACE_COUNTER_RX,
+     vlib_get_thread_index (), nif->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 (netmap_input_node) (vlib_main_t * vm,
+				  vlib_node_runtime_t * node,
+				  vlib_frame_t * frame)
+{
+  int i;
+  u32 n_rx_packets = 0;
+  u32 thread_index = vm->thread_index;
+  netmap_main_t *nm = &netmap_main;
+  netmap_if_t *nmi;
+
+  for (i = 0; i < vec_len (nm->interfaces); i++)
+    {
+      nmi = vec_elt_at_index (nm->interfaces, i);
+      if (nmi->is_admin_up &&
+	  (i % nm->input_cpu_count) ==
+	  (thread_index - nm->input_cpu_first_index))
+	n_rx_packets += netmap_device_input_fn (vm, node, frame, nmi);
+    }
+
+  return n_rx_packets;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (netmap_input_node) = {
+  .name = "netmap-input",
+  .sibling_of = "device-input",
+  .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
+  .format_trace = format_netmap_input_trace,
+  .type = VLIB_NODE_TYPE_INPUT,
+  /* default state is INTERRUPT mode, switch to POLLING if worker threads are enabled */
+  .state = VLIB_NODE_STATE_INTERRUPT,
+  .n_errors = NETMAP_INPUT_N_ERROR,
+  .error_strings = netmap_input_error_strings,
+};
+/* *INDENT-ON* */
+
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */