samples: Add an IPv6 '-6' option to the pktgen scripts

Add a '-6' option to the sample pktgen scripts for sending out
IPv6 packets.

[root@kerneldev010.prn1 ~/pktgen]# ./pktgen_sample03_burst_single_flow.sh -i eth0 -s 64 -d fe80::f652:14ff:fec2:a14c -m f4:52:14:c2:a1:4c -b 32 -6

[root@kerneldev011.prn1 ~]# tcpdump -i eth0 -nn -c3 port 9
tcpdump: WARNING: eth0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
14:38:51.815297 IP6 fe80::f652:14ff:fec2:2ad2.9 > fe80::f652:14ff:fec2:a14c.9: UDP, length 16
14:38:51.815311 IP6 fe80::f652:14ff:fec2:2ad2.9 > fe80::f652:14ff:fec2:a14c.9: UDP, length 16
14:38:51.815313 IP6 fe80::f652:14ff:fec2:2ad2.9 > fe80::f652:14ff:fec2:a14c.9: UDP, length 16

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/samples/pktgen/parameters.sh b/samples/pktgen/parameters.sh
index 33b70fd..f70ea7d 100644
--- a/samples/pktgen/parameters.sh
+++ b/samples/pktgen/parameters.sh
@@ -14,12 +14,13 @@
     echo "  -b : (\$BURST)     HW level bursting of SKBs"
     echo "  -v : (\$VERBOSE)   verbose"
     echo "  -x : (\$DEBUG)     debug"
+    echo "  -6 : (\$IP6)       IPv6"
     echo ""
 }
 
 ##  --- Parse command line arguments / parameters ---
 ## echo "Commandline options:"
-while getopts "s:i:d:m:t:c:b:vxh" option; do
+while getopts "s:i:d:m:t:c:b:vxh6" option; do
     case $option in
         i) # interface
           export DEV=$OPTARG
@@ -59,6 +60,10 @@
           export DEBUG=yes
           info "Debug mode: DEBUG=$DEBUG"
           ;;
+	6)
+	  export IP6=6
+	  info "IP6: IP6=$IP6"
+	  ;;
         h|?|*)
           usage;
           err 2 "[ERROR] Unknown parameters!!!"