`tcpreplay-edit` incorrectly rewrites layer 3 length field to include Ethernet padding

[iczero]

`tcpreplay-edit` incorrectly rewrites layer 3 length field to include Ethernet padding

[ChuckCottrill]

This is related to the issue #844
The defect was introduced in 4.4.1, and tcprewrite worked in 4.4.0.

[iczero]

@ChuckCottrill Tested PR, looks like it fixes this issue. Thank you for the help.

[iczero]

To get a pcap with the padding, it's likely easiest to do sysctl -w net.ipv4.tcp_timestamps=0 and do a capture of a TCP connection.

[ChuckCottrill]

Based upon my investigation, the packet length "fix" was introduced due to issue #703.
Although the function fix_ipv4_length() existed previously, it was not called.
Our organization had a similar issue with the step from version 4.4.0 to version 4.4.1
This does not fix the length calculation, but does avoid the problem.

[ChuckCottrill]

Please check whether PR #846 resolves your issue.