Robert Allan JamesandClaude Sonnet 5
f4615cf605
is_member() (fail-closed) and add() (idempotent, chains new devblocks onto the tail as needed) over the item-17 eligibility-list devblock chain, mirroring capsule_zuse_boot.c's magic/version/CRC-64 validation convention. No callers yet. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01QgooKd5hJNtTYqB6CyK5f9
108 lines
4.5 KiB
C
108 lines
4.5 KiB
C
/*
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StarForth — Steady-State Virtual Machine Runtime
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Copyright (c) 2023–2025 Robert A. James
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All rights reserved.
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Licensed under the StarForth License, Version 1.0
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*/
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#ifndef __STARKERNEL__
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#error "zuse_eligibility.c is kernel-only"
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#endif
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#include "starkernel/zuse_eligibility.h"
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#include "starkernel/zuse_eligibility_list.h"
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#include "block_subsystem.h" /* compute_crc64(), blk_meta_zone_read/write */
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#include <string.h>
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#include <stddef.h>
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/* Read and validate one devblock of the chain. Mirrors
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* capsule_zuse_boot.c's genesis_marker_read() convention exactly: magic
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* mismatch, version mismatch, and CRC mismatch are all merged into a
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* single -1 ("treat as absent/corrupt, not present") -- the fence region
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* is never zeroed at format time (block_subsystem.c's blk_commit_format()
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* only zeroes BAM/reloc), so blank foreign bytes and genuine corruption
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* are indistinguishable and must be handled identically here. */
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static int list_devblock_read(uint32_t devblock_from_top, zuse_eligibility_devblock_t *out) {
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if (blk_meta_zone_read(devblock_from_top, (uint8_t *)out) != 0) return -1;
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if (out->magic != ZUSE_ELIGIBILITY_LIST_MAGIC) return -1;
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if (out->version != ZUSE_ELIGIBILITY_LIST_VERSION) return -1;
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if (out->count > ZUSE_ELIGIBILITY_ENTRIES_PER_DEVBLOCK) return -1;
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uint64_t want_crc = compute_crc64((const uint8_t *)out,
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offsetof(zuse_eligibility_devblock_t, crc));
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if (want_crc != out->crc) return -1;
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return 0;
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}
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static int list_devblock_write(uint32_t devblock_from_top, zuse_eligibility_devblock_t *blk) {
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blk->crc = compute_crc64((const uint8_t *)blk, offsetof(zuse_eligibility_devblock_t, crc));
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return blk_meta_zone_write(devblock_from_top, (const uint8_t *)blk) == 0 ? 0 : -1;
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}
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int zuse_eligibility_is_member(const uint8_t pubkey[32]) {
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uint32_t devblock = ZUSE_ELIGIBILITY_LIST_HEAD_DEVBLOCK;
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zuse_eligibility_devblock_t blk;
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for (;;) {
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if (list_devblock_read(devblock, &blk) != 0) return 0; /* fail-closed */
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for (uint32_t i = 0; i < blk.count; i++) {
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if (memcmp(blk.entries[i], pubkey, 32) == 0) return 1;
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}
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if (blk.next_devblock_from_top == ZUSE_ELIGIBILITY_LIST_NO_NEXT) return 0;
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devblock = blk.next_devblock_from_top;
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}
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}
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int zuse_eligibility_add(const uint8_t pubkey[32]) {
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uint32_t devblock = ZUSE_ELIGIBILITY_LIST_HEAD_DEVBLOCK;
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zuse_eligibility_devblock_t blk;
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if (list_devblock_read(devblock, &blk) != 0) {
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/* List doesn't exist yet (blank fence, or this is genuinely the
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* first entry ever added) -- create the head devblock fresh. */
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memset(&blk, 0, sizeof(blk));
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blk.magic = ZUSE_ELIGIBILITY_LIST_MAGIC;
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blk.version = ZUSE_ELIGIBILITY_LIST_VERSION;
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blk.count = 1;
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blk.next_devblock_from_top = ZUSE_ELIGIBILITY_LIST_NO_NEXT;
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memcpy(blk.entries[0], pubkey, 32);
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return list_devblock_write(devblock, &blk);
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}
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/* Walk the existing chain: bail out early (idempotent success) if
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* already present, otherwise track the tail devblock to append to. */
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for (;;) {
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for (uint32_t i = 0; i < blk.count; i++) {
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if (memcmp(blk.entries[i], pubkey, 32) == 0) return 0; /* already eligible */
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}
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if (blk.next_devblock_from_top == ZUSE_ELIGIBILITY_LIST_NO_NEXT) break;
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devblock = blk.next_devblock_from_top;
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if (list_devblock_read(devblock, &blk) != 0) return -1; /* corrupt mid-chain */
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}
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if (blk.count < ZUSE_ELIGIBILITY_ENTRIES_PER_DEVBLOCK) {
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memcpy(blk.entries[blk.count], pubkey, 32);
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blk.count++;
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return list_devblock_write(devblock, &blk);
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}
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/* Tail devblock is full -- chain a fresh one drawn from the
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* already-reserved fence budget, one devblock_from_top past the
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* current tail (blk_meta_zone_write() itself refuses any offset at
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* or beyond the on-disk meta_fence_blocks reservation, so an
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* exhausted budget surfaces here as an ordinary write failure). */
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uint32_t new_devblock = devblock + 1;
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zuse_eligibility_devblock_t new_blk;
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memset(&new_blk, 0, sizeof(new_blk));
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new_blk.magic = ZUSE_ELIGIBILITY_LIST_MAGIC;
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new_blk.version = ZUSE_ELIGIBILITY_LIST_VERSION;
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new_blk.count = 1;
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new_blk.next_devblock_from_top = ZUSE_ELIGIBILITY_LIST_NO_NEXT;
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memcpy(new_blk.entries[0], pubkey, 32);
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if (list_devblock_write(new_devblock, &new_blk) != 0) return -1;
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blk.next_devblock_from_top = new_devblock;
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return list_devblock_write(devblock, &blk);
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}
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