Add service to tcpdump during run
This adds a service to run a tcpdump during the run. This can be
useful to capture various network traffic for post analysis.
There didn't seem to quite be an appropriate place to document it, so
a new debugging file is started, with some terse explaination of our
various system-wide debugging services.
Change-Id: I09aaa57611c5047d09a9bce7932d34e9d50b30e6
diff --git a/lib/tcpdump b/lib/tcpdump
new file mode 100644
index 0000000..16e8269
--- /dev/null
+++ b/lib/tcpdump
@@ -0,0 +1,43 @@
+#!/bin/bash
+#
+# lib/tcpdump
+# Functions to start and stop a tcpdump
+
+# Dependencies:
+#
+# - ``functions`` file
+
+# ``stack.sh`` calls the entry points in this order:
+#
+# - start_tcpdump
+# - stop_tcpdump
+
+# Save trace setting
+_XTRACE_TCPDUMP=$(set +o | grep xtrace)
+set +o xtrace
+
+TCPDUMP_OUTPUT=${TCPDUMP_OUTPUT:-$LOGDIR/tcpdump.pcap}
+
+# e.g. for iscsi
+# "-i any tcp port 3260"
+TCPDUMP_ARGS=${TCPDUMP_ARGS:-""}
+
+# start_tcpdump() - Start running processes
+function start_tcpdump {
+ # Run a tcpdump with given arguments and save the packet capture
+ if is_service_enabled tcpdump; then
+ if [[ -z "${TCPDUMP_ARGS}" ]]; then
+ die $LINENO "The tcpdump service requires TCPDUMP_ARGS to be set"
+ fi
+ touch ${TCPDUMP_OUTPUT}
+ run_process tcpdump "/usr/sbin/tcpdump -w $TCPDUMP_OUTPUT $TCPDUMP_ARGS" root root
+ fi
+}
+
+# stop_tcpdump() stop tcpdump process
+function stop_tcpdump {
+ stop_process tcpdump
+}
+
+# Restore xtrace
+$_XTRACE_TCPDUMP