defrag: remove unnecessary copy operations

[shizishizi2012]

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Link to redmine ticket: No

Describe changes:

• When reassembling the IPv6 fragment, there is no need to copy the last fragment data to the new packet. Fixing that.

#suricata-verify-pr: #suricata-verify-repo: #suricata-verify-branch: #suricata-update-pr: #suricata-update-repo: #suricata-update-branch: #libhtp-pr: #libhtp-repo: #libhtp-branch:

[codecov[bot]]

Codecov Report

Merging #6246 (621fac4) into master (b8499de) will decrease coverage by 0.01%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #6246      +/-   ##
==========================================
- Coverage   76.94%   76.93%   -0.02%     
==========================================
  Files         611      611              
  Lines      186146   186145       -1     
==========================================
- Hits       143236   143214      -22     
- Misses      42910    42931      +21     

Flag	Coverage Δ
fuzzcorpus	52.84% <100.00%> (+0.02%)	:arrow_up:
suricata-verify	51.09% <0.00%> (-0.06%)	:arrow_down:
unittests	63.08% <100.00%> (-0.01%)	:arrow_down:

Flags with carried forward coverage won't be shown. Click here to find out more.

[jasonish]

Thanks @shizishizi2012. Can you please elaborate in the git commit why they copy is not needed? Thanks!

[shizishizi2012]

Thanks @shizishizi2012. Can you please elaborate in the git commit why they copy is not needed? Thanks!

The content of they copy will be covered by the IP fragment of the subsequent circular copy.

[catenacyber]

@shizishizi2012 are you planning further work on this ?