Move the vnet cdp protocol implementation to a plugin

Add a binary API and debug cli to enable/disable cdp. cdp is disabled
by default.

Change-Id: I307c7e38dfda38e36ff3325f65de7036c34d89b1
Signed-off-by: Dave Barach <dave@barachs.net>

1 files changed, 215 insertions, 0 deletions

diff --git a/src/plugins/cdp/cdp_node.c b/src/plugins/cdp/cdp_node.c
new file mode 100644
index 00000000000..1336c567287
--- /dev/null
+++ b/src/plugins/cdp/cdp_node.c
@@ -0,0 +1,215 @@
+/*
+ * Copyright (c) 2011-2018 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 <cdp/cdp.h>
+#include <vnet/ethernet/packet.h>
+
+/** \file
+
+    2 x CDP graph nodes: an "interior" node to process
+    incoming announcements, and a "process" node to periodically
+    send announcements.
+
+    The interior node is neither pipelined nor dual-looped, because
+    it would be very unusual to see more than one CDP packet in
+    a given input frame. So, it's a very simple / straighforward
+    example.
+*/
+
+/*
+ * packet counter strings
+ * Dump these counters via the "show error" CLI command
+ */
+static char *cdp_error_strings[] = {
+#define _(sym,string) string,
+  foreach_cdp_error
+#undef _
+};
+
+/*
+ * We actually send all cdp pkts to the "error" node after scanning
+ * them, so the graph node has only one next-index. The "error-drop"
+ * node automatically bumps our per-node packet counters for us.
+ */
+typedef enum
+{
+  CDP_INPUT_NEXT_NORMAL,
+  CDP_INPUT_N_NEXT,
+} cdp_next_t;
+
+/*
+ * Process a frame of cdp packets
+ * Expect 1 packet / frame
+ */
+static uword
+cdp_node_fn (vlib_main_t * vm,
+	     vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  u32 n_left_from, *from;
+  cdp_input_trace_t *t0;
+
+  from = vlib_frame_vector_args (frame);	/* array of buffer indices */
+  n_left_from = frame->n_vectors;	/* number of buffer indices */
+
+  while (n_left_from > 0)
+    {
+      u32 bi0;
+      vlib_buffer_t *b0;
+      u32 next0, error0;
+
+      bi0 = from[0];
+      b0 = vlib_get_buffer (vm, bi0);
+
+      next0 = CDP_INPUT_NEXT_NORMAL;
+
+      /* scan this cdp pkt. error0 is the counter index to bump */
+      error0 = cdp_input (vm, b0, bi0);
+      b0->error = node->errors[error0];
+
+      /* If this pkt is traced, snapshoot the data */
+      if (b0->flags & VLIB_BUFFER_IS_TRACED)
+	{
+	  int len;
+	  t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
+	  len = (b0->current_length < sizeof (t0->data))
+	    ? b0->current_length : sizeof (t0->data);
+	  t0->len = len;
+	  clib_memcpy (t0->data, vlib_buffer_get_current (b0), len);
+	}
+      /* push this pkt to the next graph node, always error-drop */
+      vlib_set_next_frame_buffer (vm, node, next0, bi0);
+
+      from += 1;
+      n_left_from -= 1;
+    }
+
+  return frame->n_vectors;
+}
+
+/*
+ * cdp input graph node declaration
+ */
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (cdp_input_node, static) = {
+  .function = cdp_node_fn,
+  .name = "cdp-input",
+  .vector_size = sizeof (u32),
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = CDP_N_ERROR,
+  .error_strings = cdp_error_strings,
+
+  .format_trace = cdp_input_format_trace,
+
+  .n_next_nodes = CDP_INPUT_N_NEXT,
+  .next_nodes = {
+    [CDP_INPUT_NEXT_NORMAL] = "error-drop",
+  },
+};
+/* *INDENT-ON* */
+
+/*
+ * cdp periodic function
+ */
+static uword
+cdp_process (vlib_main_t * vm, vlib_node_runtime_t * rt, vlib_frame_t * f)
+{
+  cdp_main_t *cm = &cdp_main;
+  f64 poll_time_remaining;
+  uword event_type, *event_data = 0;
+
+  /* So we can send events to the cdp process */
+  cm->cdp_process_node_index = cdp_process_node.index;
+
+  /* Dynamically register the cdp input node with the snap classifier */
+  snap_register_input_protocol (vm, "cdp-input", 0xC /* ieee_oui, Cisco */ ,
+				0x2000 /* protocol CDP */ ,
+				cdp_input_node.index);
+
+  snap_register_input_protocol (vm, "cdp-input", 0xC /* ieee_oui, Cisco */ ,
+				0x2004 /* protocol CDP */ ,
+				cdp_input_node.index);
+
+#if 0				/* retain for reference */
+  /* with the hdlc classifier */
+  hdlc_register_input_protocol (vm, HDLC_PROTOCOL_cdp, cdp_input_node.index);
+#endif
+
+  /* with ethernet input (for SRP) */
+  ethernet_register_input_type (vm, ETHERNET_TYPE_CDP /* CDP */ ,
+				cdp_input_node.index);
+
+  /* Start w/ cdp effectively disabled */
+  poll_time_remaining = 86400.0;
+
+  while (1)
+    {
+      /* sleep until next poll time, or msg serialize event occurs */
+      poll_time_remaining =
+	vlib_process_wait_for_event_or_clock (vm, poll_time_remaining);
+
+      event_type = vlib_process_get_events (vm, &event_data);
+      switch (event_type)
+	{
+	case ~0:		/* no events => timeout */
+	  break;
+
+	case CDP_EVENT_ENABLE:
+	  poll_time_remaining = 10.0;
+	  break;
+
+	case CDP_EVENT_DISABLE:
+	  poll_time_remaining = 86400.0;
+	  break;
+
+	default:
+	  clib_warning ("BUG: event type 0x%wx", event_type);
+	  break;
+	}
+      vec_reset_length (event_data);
+
+      /* peer timeout scan, send announcements */
+      if (vlib_process_suspend_time_is_zero (poll_time_remaining))
+	{
+	  cdp_periodic (vm);
+	  poll_time_remaining = 10.0;
+	}
+    }
+
+  return 0;
+}
+
+/*
+ * cdp periodic node declaration
+ */
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (cdp_process_node) = {
+  .function = cdp_process,
+  .type = VLIB_NODE_TYPE_PROCESS,
+  .name = "cdp-process",
+};
+/* *INDENT-ON* */
+
+void
+vnet_cdp_node_reference (void)
+{
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */