selftests/bpf: Expose and rename debug argument

Launching xdpxceiver with -D enables what was formerly know as 'debug'
mode. Rename this mode to 'dump-pkts' as it better describes the
behavior enabled by the option. New usage:

./xdpxceiver .. -D
or
./xdpxceiver .. --dump-pkts

Also make it possible to pass this flag to the app via the test_xsk.sh
shell script like so:

./test_xsk.sh -D
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210223162304.7450-3-ciara.loftus@intel.com

tools/testing/selftests/bpf/test_xsk.sh

@@ -74,14 +74,18 @@
 #
 # Run with verbose output:
 #   sudo ./test_xsk.sh -v
+#
+# Run and dump packet contents:
+#   sudo ./test_xsk.sh -D
 
 . xsk_prereqs.sh
 
-while getopts "cv" flag
+while getopts "cvD" flag
 do
 	case "${flag}" in
 		c) colorconsole=1;;
 		v) verbose=1;;
+		D) dump_pkts=1;;
 	esac
 done
 
@@ -138,6 +142,10 @@ if [[ $verbose -eq 1 ]]; then
 	VERBOSE_ARG="-v"
 fi
 
+if [[ $dump_pkts -eq 1 ]]; then
+	DUMP_PKTS_ARG="-D"
+fi
+
 test_status $retval "${TEST_NAME}"
 
 ## START TESTS

tools/testing/selftests/bpf/xdpxceiver.c

@@ -58,7 +58,7 @@
  * - Rx thread verifies if all 10k packets were received and delivered in-order,
  *   and have the right content
  *
- * Enable/disable debug mode:
+ * Enable/disable packet dump mode:
  * --------------------------
  * To enable L2 - L4 headers and payload dump of each packet on STDOUT, add
  * parameter -D to params array in test_xsk.sh, i.e. params=("-S" "-D")
@@ -340,7 +340,7 @@ static struct option long_options[] = {
 	{"copy", no_argument, 0, 'c'},
 	{"tear-down", no_argument, 0, 'T'},
 	{"bidi", optional_argument, 0, 'B'},
-	{"debug", optional_argument, 0, 'D'},
+	{"dump-pkts", optional_argument, 0, 'D'},
 	{"verbose", no_argument, 0, 'v'},
 	{"tx-pkt-count", optional_argument, 0, 'C'},
 	{0, 0, 0, 0}
@@ -359,7 +359,7 @@ static void usage(const char *prog)
 	    "  -c, --copy           Force copy mode\n"
 	    "  -T, --tear-down      Tear down sockets by repeatedly recreating them\n"
 	    "  -B, --bidi           Bi-directional sockets test\n"
-	    "  -D, --debug          Debug mode - dump packets L2 - L5\n"
+	    "  -D, --dump-pkts      Dump packets L2 - L5\n"
 	    "  -v, --verbose        Verbose output\n"
 	    "  -C, --tx-pkt-count=n Number of packets to send\n";
 	ksft_print_msg(str, prog);

tools/testing/selftests/bpf/xsk_prereqs.sh

@@ -128,5 +128,6 @@ execxdpxceiver()
 			copy[$index]=${!current}
 		done
 
-	./${XSKOBJ} -i ${VETH0} -i ${VETH1},${NS1} ${copy[*]} -C ${NUMPKTS} ${VERBOSE_ARG}
+	./${XSKOBJ} -i ${VETH0} -i ${VETH1},${NS1} ${copy[*]} -C ${NUMPKTS} ${VERBOSE_ARG} \
+		${DUMP_PKTS_ARG}
 }