crafted-pkt/retransmit-overlap.py: test for bug 13523

Used for crafting the capture in
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=13523#c1

1 files changed, 43 insertions, 0 deletions

diff --git a/crafted-pkt/retransmit-overlap.py b/crafted-pkt/retransmit-overlap.py
new file mode 100755
index 0000000..31fcfc5
--- /dev/null
+++ b/crafted-pkt/retransmit-overlap.py
@@ -0,0 +1,43 @@
+#!/usr/bin/env python
+import argparse
+
+from scapy.all import *
+
+parser = argparse.ArgumentParser()
+parser.add_argument("-w", dest="output_file", required=True,
+                    help="Output pcap file")
+args = parser.parse_args()
+
+
+pkttime = 0
+
+
+def tcp(data=b'', datalen=0, seq=None, rexmit=False):
+    assert len(data) == datalen
+    global pkttime
+    relseq = seq
+    seq += 4096
+    ip = IP(src='10.0.0.2', dst='10.0.0.1')
+    pkt = ip/TCP(flags='A', sport=32323, dport=25, ack=1024, seq=seq)/data
+    if rexmit:
+        pkttime += .1
+    else:
+        pkttime += .01
+    pkt.time = pkttime
+    return pkt
+
+
+pkts = [
+    tcp(seq=0,      data=b'DATA\r\n', datalen=6),
+    tcp(seq=6,      data=b'To: <root@example.com>\r\n\r\n', datalen=26),
+    tcp(seq=32,     data=b'1:segment that is fully rexmit.\n', datalen=32),
+    tcp(seq=32,     data=b'1:segment that is fully rexmit.\n'+b'2', datalen=33, rexmit=True),
+    tcp(seq=64,     data=b'2:first char (2) part of rexmit\n', datalen=32, rexmit=True),
+    tcp(seq=96,     data=b"3:line that isn't retransmitted\n", datalen=32),
+    tcp(seq=128,    data=b"4:retransmission after this:XYZ\n", datalen=32),
+    tcp(seq=160-4,  data=b"XYZ\n"+b"5:new part after retransmission\n", datalen=4+32, rexmit=True),
+    tcp(seq=192,    data=b"6:FINAL LINE, NOT RETRANSMITTED\n", datalen=32),
+    tcp(seq=224,    data=b'\r\n.\r\n', datalen=5),
+]
+
+wrpcap(args.output_file, pkts)