pcap-based dispatch tracer

To facilitate dispatch trajectory tracing, vlib_buffer_t decoding, etc.
through Wireshark

Change-Id: I31356b9fa1f40cba8830aaf10a86a9fbb7546438
Signed-off-by: Dave Barach <dave@barachs.net>

1 files changed, 100 insertions, 0 deletions

diff --git a/src/vppinfra/pcap_funcs.h b/src/vppinfra/pcap_funcs.h
new file mode 100644
index 00000000000..364f4be2333
--- /dev/null
+++ b/src/vppinfra/pcap_funcs.h
@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2015 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.
+ */
+
+#ifndef included_vppinfra_pcap_funcs_h
+#define included_vppinfra_pcap_funcs_h
+
+/** Write out data to output file. */
+clib_error_t *pcap_write (pcap_main_t * pm);
+
+/** Read data from file. */
+clib_error_t *pcap_read (pcap_main_t * pm);
+
+/**
+ * @brief Add packet
+ *
+ * @param *pm - pcap_main_t
+ * @param time_now - f64
+ * @param n_bytes_in_trace - u32
+ * @param n_bytes_in_packet - u32
+ *
+ * @return Packet Data
+ *
+ */
+static inline void *
+pcap_add_packet (pcap_main_t * pm,
+		 f64 time_now, u32 n_bytes_in_trace, u32 n_bytes_in_packet)
+{
+  pcap_packet_header_t *h;
+  u8 *d;
+
+  vec_add2 (pm->pcap_data, d, sizeof (h[0]) + n_bytes_in_trace);
+  h = (void *) (d);
+  h->time_in_sec = time_now;
+  h->time_in_usec = 1e6 * (time_now - h->time_in_sec);
+  h->n_packet_bytes_stored_in_file = n_bytes_in_trace;
+  h->n_bytes_in_packet = n_bytes_in_packet;
+  pm->n_packets_captured++;
+  return h->data;
+}
+
+/**
+ * @brief Add buffer (vlib_buffer_t) to the trace
+ *
+ * @param *pm - pcap_main_t
+ * @param *vm - vlib_main_t
+ * @param buffer_index - u32
+ * @param n_bytes_in_trace - u32
+ *
+ */
+static inline void
+pcap_add_buffer (pcap_main_t * pm,
+		 struct vlib_main_t *vm, u32 buffer_index,
+		 u32 n_bytes_in_trace)
+{
+  vlib_buffer_t *b = vlib_get_buffer (vm, buffer_index);
+  u32 n = vlib_buffer_length_in_chain (vm, b);
+  i32 n_left = clib_min (n_bytes_in_trace, n);
+  f64 time_now = vlib_time_now (vm);
+  void *d;
+
+  if (PREDICT_TRUE (pm->n_packets_captured < pm->n_packets_to_capture))
+    {
+      clib_spinlock_lock_if_init (&pm->lock);
+      d = pcap_add_packet (pm, time_now, n_left, n);
+      while (1)
+	{
+	  u32 copy_length = clib_min ((u32) n_left, b->current_length);
+	  clib_memcpy_fast (d, b->data + b->current_data, copy_length);
+	  n_left -= b->current_length;
+	  if (n_left <= 0)
+	    break;
+	  d += b->current_length;
+	  ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT);
+	  b = vlib_get_buffer (vm, b->next_buffer);
+	}
+      clib_spinlock_unlock_if_init (&pm->lock);
+    }
+}
+
+#endif /* included_vppinfra_pcap_funcs_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */