LithosAnanake/kernel/include/starkernel/capsule_wirebind.h

/*
  StarForth — Steady-State Virtual Machine Runtime

  Copyright (c) 2023–2025 Robert A. James
  All rights reserved.

  Licensed under the StarForth License, Version 1.0
*/

/**
 * capsule_wirebind.h - WIREBIND: the real thumbdrive-attach call site
 * (FABRIC-2.md §F.5/§F.23). Assembles pieces already built and
 * individually verified this session -- CERTVERIFY (vm_identity.h's
 * vm_identity_from_cert()), RUNCAP (capsule_runcap.h), the console-VM +
 * user-VM pair (capsule_console.h, sk_repl_dispatch_line() in repl.c) --
 * into one automatic sequence, replacing the RUNCAP-TEST/PAIR-TEST
 * diagnostic words that exercised each piece by hand.
 */

#ifndef STARKERNEL_CAPSULE_WIREBIND_H
#define STARKERNEL_CAPSULE_WIREBIND_H

#ifdef __STARKERNEL__

#include "starkernel/homeblocks_sig.h"
#include "starkernel/vm_identity.h"
#include "vm.h"

struct blkio_dev;

/**
 * capsule_wirebind_verify_cert - Read the cert region off dev and verify
 * it against mama_vm's own Zuse identity. Shared by both
 * capsule_wirebind_try_attach() (the original attach) and BINDSTEP
 * (mama_word_use(), mama_forth_words.c -- re-verifies live on every USE
 * of an identity-locked VM, per FABRIC-2.md §F.9 decision 1) so both
 * call sites check the exact same thing the exact same way.
 *
 * No-op-and-fail (-1) if sig->cert_offset is 0 (no cert region -- a
 * genesis-mode Zuse drive, or simply not a regular identity drive) or
 * mama_vm has no installed Zuse cert yet.
 *
 * @param dev     Already-open block device to read the cert from.
 * @param sig     Its already-checked homeblocks_sig_t.
 * @param mama_vm Hera's own VM -- the trust root (zuse_cert_pubkey).
 * @param out     Filled with the verified identity on success.
 * @return 0 on success, -1 on any failure (read, verify, or precondition).
 */
int capsule_wirebind_verify_cert(struct blkio_dev *dev,
                                  const homeblocks_sig_t *sig,
                                  VM *mama_vm, VMIdentity *out);

/**
 * capsule_wirebind_try_attach - Try to verify and bind a just-attached
 * regular (non-Zuse) identity drive.
 *
 * No-op if sig->cert_offset is 0 (a genesis-mode Zuse drive has no cert
 * region -- that's capsule_zuse_boot_try_attach()'s own job, not this
 * one's) or if mama_vm has no installed Zuse cert yet (nothing to verify
 * the attached cert against). Otherwise: reads the cert devblock(s),
 * calls vm_identity_from_cert() against mama_vm's own zuse_cert_pubkey
 * and sig->drive_uuid. On success, reads the drive's own
 * user_identity_seed_t for its username and births a console VM +
 * RUNCAP-born user VM pair (idempotent -- no-ops if that username is
 * already live this session), installs the verified VMIdentity onto the
 * user VM, and registers the "<username>~user" pairing
 * (sk_repl_dispatch_line(), repl.c, looks for this). Does NOT USE the
 * new console automatically -- that stays an explicit, later,
 * ACL-gated step (BINDSTEP, §F.9), not something a bare attach should
 * trigger silently.
 *
 * @param dev     The just-attached, already-open block device.
 * @param sig     Its already-checked homeblocks_sig_t.
 * @param mama_vm Hera's own VM (the verifier -- her zuse_cert_pubkey is
 *                the trust root regular user certs are checked against).
 */
void capsule_wirebind_try_attach(struct blkio_dev *dev,
                                  const homeblocks_sig_t *sig,
                                  VM *mama_vm);

/**
 * capsule_wirebind_eject - Graceful detach of whatever VM is currently
 * attached via the home-blocks USB path (FABRIC-2.md §F.10, decision 1).
 * The drive is still physically present when this runs.
 *
 * Sequence: resolve the tracked attached-VM id to a live registry entry
 * (no-op, returns -1, if nothing is tracked or the entry is already
 * dead/gone -- capsule_vm_kill()'s own idempotency covers a VM already
 * killed by some other path); blk_vm_flush_all() while the VM is still
 * alive; if the console's active VM is this same VM, reset it to Hera
 * (sk_repl_set_active_vm(NULL)) *before* teardown -- required, not
 * optional, to avoid a dangling console pointer; capsule_vm_kill() by
 * name; clear the tracked state.
 *
 * EJECT is inherently about "whichever identity is currently paired to
 * the one physical console" -- targets that singleton, no name argument.
 * (Corrected 2026-09-14: this used to claim a "single-USB-device
 * constraint (§F.8)" meant there was never more than one candidate --
 * stale even at the time this correction was written; §XV/§XVI
 * (2026-09-11/12) proved 9 identities genuinely simultaneously live via
 * this same attach path. EJECT staying console-singleton-scoped is a
 * deliberate UX choice now, not a hardware constraint -- see
 * capsule_wirebind_unclean_detach()'s own doc below for the function
 * that DOES need to reach every live identity, not just this one.)
 *
 * @return 0 on success, -1 if nothing was attached to eject.
 */
int capsule_wirebind_eject(void);

/**
 * capsule_wirebind_unclean_detach - Abrupt-path counterpart to
 * capsule_wirebind_eject() (FABRIC-2.md §F.10, decision 2 -- the UNCLEAN
 * node, closed alongside EJECT). Called from the existing
 * bot_msc_detach_pending hot-unplug signal (repl.c) -- the device is
 * already gone by the time this runs, so no flush is attempted; data
 * since the last flush is lost, which is correct unclean-removal
 * semantics.
 *
 * FABRIC-3.md §VII follow-on, 2026-09-06: requires the departing device
 * to actually be one WIREBIND is tracking -- a real bug otherwise, found
 * live once genuine multi-device attach made a *different* device's
 * detach reachable while a WIREBIND user's own stayed attached.
 *
 * FABRIC-3.md §XXVIII Stage 4, 2026-09-14: resolves the departing device
 * against a per-device live-identity table now, not the single
 * console-pairing global capsule_wirebind_eject() uses -- with several
 * identities simultaneously live (§XV/§XVI), any one of them can be the
 * device that just disappeared, not only the most recently attached.
 * Refuses (rather than freeing) a VM currently VM_STATE_SWITCHED_OUT --
 * see capsule_vm_kill()'s own guard -- leaving it tracked for the Stage 3
 * switcher to reap on its own next resume attempt instead.
 *
 * @param dev The device that just detached; every other value is a no-op.
 */
void capsule_wirebind_unclean_detach(struct blkio_dev *dev);

/**
 * capsule_wirebind_attached_username - The plain username (no "~user"
 * registry-name suffix) of whichever identity is currently tracked as
 * attached, or NULL if none is (FABRIC-2.md §I.1/4.4s -- the `(user)`
 * console prompt segment reads this). Points into WIREBIND's own
 * internal storage; valid only until the next attach/eject/detach, same
 * caveat as console_get_vm_name().
 */
const char *capsule_wirebind_attached_username(void);

/**
 * capsule_wirebind_overflow_idle_check - FABRIC-2.md §I.2's own "overflow
 * trigger," decided and built 2026-09-05. Called once per idle tick
 * (sk_repl_idle(), repl.c, alongside blk_migration_idle_check() -- same
 * ~1 Hz cadence), same as that function's own convention.
 *
 * No-op if nothing is attached via WIREBIND. Otherwise reads the attached
 * drive's own free/total via blk_get_device_free_blocks() (real numbers:
 * a WIREBIND-attached drive is always HOMEBLOCKS_SIG_OK, i.e. already
 * STFR/v2-formatted, by the time blk_subsys_attach_device() runs on the
 * same dev pointer right after WIREBIND itself -- not PROVISIONAL, not
 * raw). If free space is below a fixed threshold AND the attached
 * identity does not already own a claim (blk_owner_has_claim() -- a disk
 * scan, not a RAM flag, so this decision survives reboot/reattach for
 * free), claims a fixed number of additional devblocks on Artemis's own
 * device via blk_firsttouch_claim() -- a one-time-per-identity extension,
 * not a growth loop, deliberately: this does not free space on the
 * user's own drive, it only extends their pool onto system-resident
 * space, so re-claiming every tick once already extended would walk
 * Artemis's device to exhaustion for no benefit.
 */
void capsule_wirebind_overflow_idle_check(void);

/**
 * capsule_wirebind_reap_idle_check - FABRIC-3.md §XXVIII Stage 4
 * (2026-09-14): sweeps the per-device live-identity table for entries
 * whose VM has been reaped (capsule_vm_force_reap(), called from the
 * Stage 3 checkpoint on a pending_reap target -- see that function's own
 * doc comment) and removes the now-stale table entry. Does NOT itself
 * free anything or call capsule_vm_kill()/force_reap() -- purely
 * bookkeeping cleanup after the fact. Called at the same ~1 Hz idle
 * cadence as capsule_wirebind_overflow_idle_check().
 */
void capsule_wirebind_reap_idle_check(void);

#endif /* __STARKERNEL__ */

#endif /* STARKERNEL_CAPSULE_WIREBIND_H */