[JarryShaw]

• Searched for similar pull requests

• Followed the coding style (pylint/mypy/isort on the changed files: nothing new on the touched lines, mypy clean, isort clean)

• make test passes, and a test case covers the change (modules listed below)

• Added a changelog entry — N/A, added centrally

• fix — corrects a defect

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Closes #1193. _make_opt_smf_dpd (HOPOPT and IPv6-Opts) now rejects an empty H-DPD hav before it sets the mode bit with hav[0] | 0x80.

• Before: HOPOPT(next=59, options=[(Option.SMF_DPD, {'mode': SMFDPDMode.H_DPD, 'hav': b''})]) raises IndexError: index out of range. IPv6_Opts does the same.
• After: ProtocolError: HOPOPT: [OptNo 8] empty Hash Assist Value (HAV) (IPv6-Opts: ... for the other class).
• Parse side: _read_opt_smf_dpd never indexes hav. A wire H-DPD option with len=0 parses to hav=b'' without raising, so it is not this defect class and is left unchanged.
• New test tests/protocols/internet/test_smf_dpd_empty_hav_unit.py: without the fix, 2 failed with IndexError. With the fix, 2 passed, 4 subtests passed.
• Also run: test_smf_dpd_mode_rebuild_unit 4 passed; test_option_roundtrip_unit 6 passed; test_ipv6_extension_runtime 3 passed; tests/project 389 passed, 1 skipped; util/run_unittest_leg.py protocols/internet 493 tests, 0 failures.

[JarryShaw]

Cross-review verdict on 602960330: GOOD TO GO (ran on Sonnet; the author ran on Opus).

• Root cause: an empty hav raised IndexError on main and now raises ProtocolError: … [OptNo 8] empty Hash Assist Value (HAV) in both classes. I re-ran this myself.
• No other output changes: non-empty H-DPD (hav of 1, 4 and 16 octets) and all I-DPD cases build byte-identically on main and the PR. A missing hav key now also raises ProtocolError, which is the same fix.
• Parse side: 3b00080080000000 parses to hav=b'' without raising. That leniency on read is acceptable, and it is not the same defect class.
• Tests: the new test fails without the fix (2 subtests). run_unittest_leg.py protocols/internet: 493 tests, 0 failures.
• Out of scope, filed separately:
  • an SMF_DPD option with len=0 at the end of the header raises TypeError;
  • RPL option 0x23 raises AttributeError.

[github-actions]

Coverage: 88.90% (unit tier, Python 3.14, 602960330, Unit Tests run success)

Package	Statements	Missed	Branches	Partial	Cover
pcapkit (top level)	104	4	20	4	93.55%
pcapkit/const	18757	1034	2342	845	90.24%
pcapkit/corekit	1878	91	580	22	94.34%
pcapkit/dumpkit	142	0	42	0	100.00%
pcapkit/foundation	2442	102	852	39	94.38%
pcapkit/interface	112	7	40	5	92.11%
pcapkit/protocols	15759	190	4028	165	98.18%
pcapkit/toolkit	487	65	144	1	85.42%
pcapkit/utilities	429	4	122	4	98.55%
pcapkit/vendor	4409	2359	1006	158	42.84%

Per-file detail: the coverage-html artifact of this run.