Spec for three ff_rss_check optimizations: port-range kernel hook migration to FreeBSD 15.0, IPv6 hash support, and rte_thash_adjust_tuple dynamic-path optimization. Spec stage only (Chinese), no code changes.

Restore the FSTACK RSS local-port selection logic in in_pcb_lport_dest and the ff_in_pcbladdr hook in in_pcbconnect (dropped during the 13.0->15.0 upgrade), adapted to 15.0 (const inpcb, merged in_pcbconnect, RT_ALL_FIBS lookups). INPLOOKUP_LPORT_RSS_CHECK is cleared at entry. Adds 0.1 unit tests and fixes a pre-existing test_ff_dpdk_if link gap (no-op ff_tcp_hpts_softclock stub).

…IPv4)

Add per-port thash ctx (ff_rss_thash_ctx_init) and ff_rss_adjust_sport that reverse-calcs a source port landing on the local queue, with a mandatory ff_rss_check re-verification (zero tolerance for wrong queue) and soft-scan fallback. Wire it as a fast path in in_pcb_lport_dest's table-miss branch, keeping the static-table hit path and macro-off native path byte-identical. Adds 0.3 unit tests incl. an EAL-backed toeplitz/softrss equivalence hit-rate probe (full-loop 100% landing).

…t v6 path)

Add ff_rss_check6/ff_rss_tbl6_*/ff_rss_adjust_sport6 with an independent v6 static table and thash ctx (36B tuple, sport@256bit), plus IPv6 rule parsing in rss_tbl config. Wire v6 into in_pcb_lport_dest as a parallel sa_family branch and into in6_pcbconnect/in6_pcbladdr, keeping the v4 RSS path byte-identical (diff +98/-0). Mandatory ff_rss_check6 re-verification; adds v6 unit tests + hit-rate probe (full-loop 100% landing).

…-machine queue verification

rss_ct issues N connects and prints the kernel-selected source ports per process/queue; ff_rss_self_queue_info exposes proc/queueid/nb_queues/reta_size (read-only). Used to verify on real NIC that selected sports land on the owning RSS queue.

…date layer3 RSS notes

Records R-A/R-B/R-C implementation (commits, functions, line numbers), 31 unit tests with v4/v6 full-loop 100% queue landing, and on-machine verification (q0/q1 200/200 land on owning queue). Notes virtio reta_size=0 thash soft-fallback and no-IPv6-net real-machine limits, both covered by unit tests.

…ed, off by default

Add config.ini [rss_check] recheck=0/1 switch. recheck=0 (default) skips the secondary ff_rss_check after rte_thash_adjust_tuple success, realizing ~100 ns/call saving (3 runs: 0.30 vs 99.4 ns/call, ~300x ratio). recheck=1 keeps R-B/R-C zero-tolerance re-verify for debug. Unit tests: 5 new cases + 04-06 enforce recheck=1 on existing hitrate; 36 run, 35 PASSED, 1 SKIPPED (microbench, ctx-unready).

Spec: docs/ff_rss_check_opt_spec/zh_cn/ 01-08 R-D sections + 10 §5-bis report. Layer3 §2.4 updated.

Two spec deliverables (docs only, no code changes):

1. ff_rss_check_opt_spec: add requirement 0.5 / milestone R-E for porting upstream commit cb9b4d4 (IP_BIND_ADDRESS_NO_PORT) to FreeBSD 15.0. 15.0 already has the connect-time RSS path (in_pcb_lport_dest with INPLOOKUP_LPORT_RSS_CHECK), so only the bind-side gates are needed: hunk1 in in_pcbbind to skip in_pcbinshash when inp_lport==0, hunk2 in in_pcbbind_setup to skip the early in_pcb_lport call. IPv6 sync is added as recommended (in6_pcbbind delayed allocation + in6_pcbconnect L515 condition relaxation). Covers 10 chapters: overview, requirement, current-state-gap, external-research, design, interface, milestone, test, baseline, review-gate.

2. freebsd_13_to_15_upgrade_spec/04 §11: add gap-scan checklist of 13.0 FSTACK customizations vs current 15.0 tree (10 items, evidence-based with file:line). Final classification: (a) port: #1 IP_BIND v4, #2 v6 sync, #6 ng_socket kldload; (b) already ported via stub: #7/#8 ipfw; (c) not applicable: #3/#4 mcast (15.0 two trees strictly layered, no out-of-bound), #5 require_unique_port (path removed), #9 if_spppsubr.c (file does not exist), #10 namei.h NDFREE (macros refactored). All line numbers verified by grep/read_file.

…ream cb9b4d4 to FreeBSD 15.0

Defer source port allocation in in_pcbbind/in6_pcbbind when port==0 so
connect() can pick an RSS-aware source port via the R-A
INPLOOKUP_LPORT_RSS_CHECK path. v6 connect outer condition is relaxed
under FSTACK to (in6p_laddr unspec || inp_lport==0) so bind-then-connect
actually enters the RSS branch; the inner in6p_laddr overwrite is now
guarded by IN6_IS_ADDR_UNSPECIFIED to preserve a user-bound v6 address.
All hunks gated by #ifdef/#ifndef FSTACK; FSTACK off retains native
FreeBSD 15.0 semantics (REUSEPORT_LB MPASS at L740 unaffected).
Baseline 13.0 contains none of these three hunks; this is a fresh
addition rather than a missed-port migration.

…eport; update layer3 RSS notes

Add §6 R-E to ff_rss_check_opt_spec/zh_cn/10-实施与验证报告.md with landing
points, build/lint, unit-test zero-regression, static call-chain trace
(v4 8 steps + v6 7 steps), on-machine limitations, and 8-gate audit.
Rename existing §6 conclusion to §7 and extend it to cover all five
optimizations (0.1/0.3/0.2/0.4/0.5). Append one-liner R-E note to
docs/03-LAYER3-FUNCTIONS.md RSS section.

…failure

Upstream FreeBSD 15.0 declares tcp_hw_highest_rate with GNU89 `inline`
(no `static`); under -O2 it is inlined away, but under -O0 (DEBUG) it
emits external references with no out-of-line definition in libfstack.a,
breaking example/ and app/nginx linking. Align with the same header's
other inline helpers which all use `static inline`.