vlib: packet tracer support for pkt thread handoffs

Type: feature

Change-Id: Ia3d9a47679202c2a47cd3746b50e86c6b8627ef6
Signed-off-by: Dave Barach <dave@barachs.net>

1 files changed, 125 insertions, 0 deletions

diff --git a/src/vlib/handoff_trace.c b/src/vlib/handoff_trace.c
new file mode 100644
index 00000000000..7a6743885da
--- /dev/null
+++ b/src/vlib/handoff_trace.c
@@ -0,0 +1,125 @@
+/*
+ * handoff_trace.c - used to generate handoff trace records
+ *
+ * Copyright (c) 2019 Cisco Systems 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 <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vppinfra/error.h>
+
+typedef struct
+{
+  u32 prev_thread;
+  u32 prev_trace_index;
+} handoff_trace_t;
+
+/* packet trace format function */
+static u8 *
+format_handoff_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 *);
+  handoff_trace_t *t = va_arg (*args, handoff_trace_t *);
+
+  s = format (s, "HANDED-OFF: from thread %d trace index %d",
+	      t->prev_thread, t->prev_trace_index);
+  return s;
+}
+
+static vlib_node_registration_t handoff_trace_node;
+
+#define foreach_handoff_trace_error \
+_(BUGS, "Warning: packets sent to the handoff trace node!")
+
+typedef enum
+{
+#define _(sym,str) HANDOFF_TRACE_ERROR_##sym,
+  foreach_handoff_trace_error
+#undef _
+    HANDOFF_TRACE_N_ERROR,
+} handoff_trace_error_t;
+
+static char *handoff_trace_error_strings[] = {
+#define _(sym,string) string,
+  foreach_handoff_trace_error
+#undef _
+};
+
+static uword
+handoff_trace_node_fn (vlib_main_t * vm,
+		       vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  vlib_buffer_free (vm, vlib_frame_vector_args (frame), frame->n_vectors);
+
+  vlib_node_increment_counter (vm, node->node_index,
+			       HANDOFF_TRACE_ERROR_BUGS, frame->n_vectors);
+
+  return frame->n_vectors;
+}
+
+typedef enum
+{
+  HANDOFF_TRACE_NEXT_DROP,
+  HANDOFF_TRACE_N_NEXT,
+} tdummy_next_t;
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (handoff_trace_node, static) =
+{
+  .name = "handoff_trace",
+  .function = handoff_trace_node_fn,
+  .vector_size = sizeof (u32),
+  .format_trace = format_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_next_nodes = HANDOFF_TRACE_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [HANDOFF_TRACE_NEXT_DROP] = "error-drop",
+  },
+
+  .n_errors = ARRAY_LEN(handoff_trace_error_strings),
+  .error_strings = handoff_trace_error_strings,
+};
+/* *INDENT-ON* */
+
+void
+vlib_add_handoff_trace (vlib_main_t * vm, vlib_buffer_t * b)
+{
+  u32 prev_thread = vlib_buffer_get_trace_thread (b);
+  u32 prev_trace_index = vlib_buffer_get_trace_index (b);
+  handoff_trace_t *t;
+  vlib_node_runtime_t *node
+    = vlib_node_get_runtime (vm, handoff_trace_node.index);
+
+  vlib_trace_buffer (vm, node, 0 /* fake next frame index */ ,
+		     b, 1 /* folllow chain */ );
+
+  t = vlib_add_trace (vm, node, b, sizeof (*t));
+
+  t->prev_thread = prev_thread;
+  t->prev_trace_index = prev_trace_index;
+}
+
+
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */