Network delay simulator plugin

Change-Id: I4a70c7df8f0cb368a4e1cb16f30eeef5c6058c79
Signed-off-by: Dave Barach <dave@barachs.net>

1 files changed, 187 insertions, 0 deletions

diff --git a/src/plugins/nsim/node.c b/src/plugins/nsim/node.c
new file mode 100644
index 00000000000..69dc9be919b
--- /dev/null
+++ b/src/plugins/nsim/node.c
@@ -0,0 +1,187 @@
+/*
+ * node.c - skeleton vpp engine plug-in dual-loop node skeleton
+ *
+ * Copyright (c) <current-year> <your-organization>
+ * 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 <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vppinfra/error.h>
+#include <nsim/nsim.h>
+
+typedef struct
+{
+  f64 expires;
+  u32 tx_sw_if_index;
+  int is_drop;
+} nsim_trace_t;
+
+#ifndef CLIB_MARCH_VARIANT
+
+/* packet trace format function */
+static u8 *
+format_nsim_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 *);
+  nsim_trace_t *t = va_arg (*args, nsim_trace_t *);
+
+  if (t->is_drop)
+    s = format (s, "NSIM: ring drop");
+  else
+    s = format (s, "NSIM: tx time %.6f sw_if_index %d",
+		t->expires, t->tx_sw_if_index);
+
+  return s;
+}
+#endif /* CLIB_MARCH_VARIANT */
+
+vlib_node_registration_t nsim_node;
+
+#define foreach_nsim_error                              \
+_(BUFFERED, "Packets buffered")                         \
+_(DROPPED, "Packets dropped due to lack of space")
+
+typedef enum
+{
+#define _(sym,str) NSIM_ERROR_##sym,
+  foreach_nsim_error
+#undef _
+    NSIM_N_ERROR,
+} nsim_error_t;
+
+#ifndef CLIB_MARCH_VARIANT
+static char *nsim_error_strings[] = {
+#define _(sym,string) string,
+  foreach_nsim_error
+#undef _
+};
+#endif /* CLIB_MARCH_VARIANT */
+
+typedef enum
+{
+  NSIM_NEXT_DROP,
+  NSIM_N_NEXT,
+} nsim_next_t;
+
+always_inline uword
+nsim_inline (vlib_main_t * vm,
+	     vlib_node_runtime_t * node, vlib_frame_t * frame, int is_trace)
+{
+  nsim_main_t *nsm = &nsim_main;
+  u32 n_left_from, *from;
+  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
+  u16 nexts[VLIB_FRAME_SIZE], *next;
+  u32 my_thread_index = vm->thread_index;
+  nsim_wheel_t *wp = nsm->wheel_by_thread[my_thread_index];
+  f64 now = vlib_time_now (vm);
+  f64 expires = now + nsm->delay;
+  int is_drop0;
+  u32 no_error = node->errors[NSIM_ERROR_BUFFERED];
+  u32 no_buffer_error = node->errors[NSIM_ERROR_DROPPED];
+  nsim_wheel_entry_t *ep = 0;
+
+  ASSERT (wp);
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+
+  vlib_get_buffers (vm, from, bufs, n_left_from);
+  b = bufs;
+  next = nexts;
+
+  /* There is no point in trying to do more than 1 pkt here */
+  while (n_left_from > 0)
+    {
+      b[0]->error = no_error;
+      next[0] = NSIM_NEXT_DROP;
+      is_drop0 = 0;
+      if (PREDICT_TRUE (wp->cursize < wp->wheel_size))
+	{
+	  ep = wp->entries + wp->tail;
+	  wp->tail++;
+	  if (wp->tail == wp->wheel_size)
+	    wp->tail = 0;
+	  wp->cursize++;
+
+	  ep->tx_time = expires;
+	  ep->tx_sw_if_index =
+	    (vnet_buffer (b[0])->sw_if_index[VLIB_RX] == nsm->sw_if_index0)
+	    ? nsm->sw_if_index1 : nsm->sw_if_index0;
+	  ep->current_length = vlib_buffer_length_in_chain (vm, b[0]);
+	  ASSERT (ep->current_length <= WHEEL_ENTRY_DATA_SIZE);
+	  clib_memcpy (ep->data, vlib_buffer_get_current (b[0]),
+		       ep->current_length);
+	}
+      else			/* out of wheel space, drop pkt */
+	b[0]->error = no_buffer_error;
+
+      if (is_trace)
+	{
+	  if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
+	    {
+	      nsim_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t));
+	      t->expires = expires;
+	      t->is_drop = is_drop0;
+	      if (is_drop0 == 0)
+		t->tx_sw_if_index = ep->tx_sw_if_index;
+	    }
+	}
+
+      b += 1;
+      next += 1;
+      n_left_from -= 1;
+    }
+  vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
+  return frame->n_vectors;
+}
+
+VLIB_NODE_FN (nsim_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
+			  vlib_frame_t * frame)
+{
+  if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
+    return nsim_inline (vm, node, frame, 1 /* is_trace */ );
+  else
+    return nsim_inline (vm, node, frame, 0 /* is_trace */ );
+}
+
+/* *INDENT-OFF* */
+#ifndef CLIB_MARCH_VARIANT
+VLIB_REGISTER_NODE (nsim_node) =
+{
+  .name = "nsim",
+  .vector_size = sizeof (u32),
+  .format_trace = format_nsim_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(nsim_error_strings),
+  .error_strings = nsim_error_strings,
+
+  .n_next_nodes = NSIM_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+        [NSIM_NEXT_DROP] = "error-drop",
+  },
+};
+#endif /* CLIB_MARCH_VARIANT */
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */