#include #ifndef TEST_STATE_COVERAGE #include #endif #include static inline bool high_priority(enum state state) { return (state & 1) == (STATE_NORMAL_HIGHPRIO & 1); } #define prio(state, name) \ (high_priority(state) ? name##_HIGHPRIO : name##_LOWPRIO) #define toggle_prio(state, name) \ (!high_priority(state) ? name##_HIGHPRIO : name##_LOWPRIO) /* STATE_CLOSE* can be treated as a bitset offset from STATE_CLOSED */ #define BITS_TO_STATE(bits) (STATE_CLOSED + (bits)) #define STATE_TO_BITS(state) ((state) - STATE_CLOSED) /* For the rare cases where state may not change */ static enum command_status next_state_nocheck(struct peer *peer, enum command_status cstatus, const enum state state) { peer->state = state; return cstatus; } static enum command_status next_state(struct peer *peer, enum command_status cstatus, const enum state state) { assert(peer->state != state); return next_state_nocheck(peer, cstatus, state); } /* * Simple marker to note we don't update state. * * This happens in two cases: * - We're ignoring packets while closing. * - We stop watching an on-chain HTLC: we indicate that we want * INPUT_NO_MORE_HTLCS when we get the last one. */ static enum command_status unchanged_state(enum command_status cstatus) { return cstatus; } /* This may not actually change the state. */ static enum command_status next_state_bits(struct peer *peer, enum command_status cstatus, unsigned int bits) { return next_state_nocheck(peer, cstatus, BITS_TO_STATE(bits)); } static void set_peer_cond(struct peer *peer, enum state_peercond cond) { assert(peer->cond != cond); peer->cond = cond; } static void change_peer_cond(struct peer *peer, enum state_peercond old, enum state_peercond new) { assert(peer->cond == old); peer->cond = new; } static void complete_cmd(struct peer *peer, enum command_status *statusp, enum command_status status) { change_peer_cond(peer, PEER_BUSY, PEER_CMD_OK); *statusp = status; } static void queue_tx_broadcast(const struct bitcoin_tx **broadcast, const struct bitcoin_tx *tx) { assert(!*broadcast); assert(tx); *broadcast = tx; } enum command_status state(struct peer *peer, const enum state_input input, const union input *idata, const struct bitcoin_tx **broadcast) { Pkt *decline; const struct bitcoin_tx *tx; Pkt *err; enum command_status cstatus = CMD_NONE; *broadcast = NULL; switch (peer->state) { /* * Initial channel opening states. */ case STATE_INIT: if (input_is(input, CMD_OPEN_WITH_ANCHOR)) { queue_pkt_open(peer, OPEN_CHANNEL__ANCHOR_OFFER__WILL_CREATE_ANCHOR); change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); return next_state(peer, cstatus, STATE_OPEN_WAIT_FOR_OPEN_WITHANCHOR); } else if (input_is(input, CMD_OPEN_WITHOUT_ANCHOR)) { change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); queue_pkt_open(peer, OPEN_CHANNEL__ANCHOR_OFFER__WONT_CREATE_ANCHOR); return next_state(peer, cstatus, STATE_OPEN_WAIT_FOR_OPEN_NOANCHOR); } break; case STATE_OPEN_WAIT_FOR_OPEN_NOANCHOR: if (input_is(input, PKT_OPEN)) { err = accept_pkt_open(peer, idata->pkt); if (err) { complete_cmd(peer, &cstatus, CMD_FAIL); goto err_close_nocleanup; } return next_state(peer, cstatus, STATE_OPEN_WAIT_FOR_ANCHOR); } else if (input_is(input, CMD_CLOSE) || input_is(input, INPUT_CONNECTION_LOST)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto instant_close; } else if (input_is_pkt(input)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto unexpected_pkt_nocleanup; } break; case STATE_OPEN_WAIT_FOR_OPEN_WITHANCHOR: if (input_is(input, PKT_OPEN)) { err = accept_pkt_open(peer, idata->pkt); if (err) { complete_cmd(peer, &cstatus, CMD_FAIL); goto err_close_nocleanup; } bitcoin_create_anchor(peer, BITCOIN_ANCHOR_CREATED); return next_state(peer, cstatus, STATE_OPEN_WAIT_FOR_ANCHOR_CREATE); } else if (input_is(input, CMD_CLOSE) || input_is(input, INPUT_CONNECTION_LOST)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto instant_close; } else if (input_is_pkt(input)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto unexpected_pkt_nocleanup; } break; case STATE_OPEN_WAIT_FOR_ANCHOR_CREATE: if (input_is(input, BITCOIN_ANCHOR_CREATED)) { queue_pkt_anchor(peer); return next_state(peer, cstatus, STATE_OPEN_WAIT_FOR_COMMIT_SIG); } else if (input_is(input, CMD_CLOSE) || input_is(input, INPUT_CONNECTION_LOST)) { bitcoin_release_anchor(peer, BITCOIN_ANCHOR_CREATED); complete_cmd(peer, &cstatus, CMD_FAIL); goto instant_close; } else if (input_is_pkt(input)) { bitcoin_release_anchor(peer, BITCOIN_ANCHOR_CREATED); complete_cmd(peer, &cstatus, CMD_FAIL); goto unexpected_pkt_nocleanup; } break; case STATE_OPEN_WAIT_FOR_ANCHOR: if (input_is(input, PKT_OPEN_ANCHOR)) { err = accept_pkt_anchor(peer, idata->pkt); if (err) { complete_cmd(peer, &cstatus, CMD_FAIL); goto err_close_nocleanup; } queue_pkt_open_commit_sig(peer); peer_watch_anchor(peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT, BITCOIN_ANCHOR_UNSPENT, BITCOIN_ANCHOR_THEIRSPEND, BITCOIN_ANCHOR_OTHERSPEND); return next_state(peer, cstatus, STATE_OPEN_WAITING_THEIRANCHOR); } else if (input_is(input, CMD_CLOSE) || input_is(input, INPUT_CONNECTION_LOST)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto instant_close; } else if (input_is_pkt(input)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto unexpected_pkt_nocleanup; } break; case STATE_OPEN_WAIT_FOR_COMMIT_SIG: if (input_is(input, PKT_OPEN_COMMIT_SIG)) { err = accept_pkt_open_commit_sig(peer, idata->pkt); if (err) { bitcoin_release_anchor(peer, INPUT_NONE); complete_cmd(peer, &cstatus, CMD_FAIL); goto err_start_unilateral_close; } queue_tx_broadcast(broadcast, bitcoin_anchor(peer)); peer_watch_anchor(peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE, BITCOIN_ANCHOR_UNSPENT, BITCOIN_ANCHOR_THEIRSPEND, BITCOIN_ANCHOR_OTHERSPEND); return next_state(peer, cstatus, STATE_OPEN_WAITING_OURANCHOR); } else if (input_is(input, CMD_CLOSE) || input_is(input, INPUT_CONNECTION_LOST)) { bitcoin_release_anchor(peer, INPUT_NONE); complete_cmd(peer, &cstatus, CMD_FAIL); goto instant_close; } else if (input_is_pkt(input)) { bitcoin_release_anchor(peer, INPUT_NONE); complete_cmd(peer, &cstatus, CMD_FAIL); goto unexpected_pkt_nocleanup; } break; case STATE_OPEN_WAITING_OURANCHOR: if (input_is(input, PKT_OPEN_COMPLETE)) { err = accept_pkt_open_complete(peer, idata->pkt); if (err) { complete_cmd(peer, &cstatus, CMD_FAIL); /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE); goto err_start_unilateral_close; } return next_state(peer, cstatus, STATE_OPEN_WAITING_OURANCHOR_THEYCOMPLETED); } /* Fall thru */ case STATE_OPEN_WAITING_OURANCHOR_THEYCOMPLETED: if (input_is(input, BITCOIN_ANCHOR_DEPTHOK)) { queue_pkt_open_complete(peer); if (peer->state == STATE_OPEN_WAITING_OURANCHOR_THEYCOMPLETED) { complete_cmd(peer, &cstatus, CMD_SUCCESS); return next_state(peer, cstatus, STATE_NORMAL_HIGHPRIO); } return next_state(peer, cstatus, STATE_OPEN_WAIT_FOR_COMPLETE_OURANCHOR); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto anchor_unspent; } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE); complete_cmd(peer, &cstatus, CMD_FAIL); goto them_unilateral; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { /* This should be impossible. */ return next_state(peer, cstatus, STATE_ERR_INFORMATION_LEAK); } else if (input_is(input, CMD_CLOSE)) { /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE); complete_cmd(peer, &cstatus, CMD_FAIL); goto start_clearing; } else if (input_is(input, INPUT_CONNECTION_LOST)) { /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE); complete_cmd(peer, &cstatus, CMD_FAIL); goto start_unilateral_close; } else if (input_is(input, PKT_CLOSE_CLEARING)) { /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE); complete_cmd(peer, &cstatus, CMD_FAIL); goto accept_clearing; } else if (input_is_pkt(input)) { /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE); complete_cmd(peer, &cstatus, CMD_FAIL); goto unexpected_pkt; } break; case STATE_OPEN_WAITING_THEIRANCHOR: if (input_is(input, PKT_OPEN_COMPLETE)) { err = accept_pkt_open_complete(peer, idata->pkt); if (err) { complete_cmd(peer, &cstatus, CMD_FAIL); /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT); goto err_start_unilateral_close; } return next_state(peer, cstatus, STATE_OPEN_WAITING_THEIRANCHOR_THEYCOMPLETED); } /* Fall thru */ case STATE_OPEN_WAITING_THEIRANCHOR_THEYCOMPLETED: if (input_is(input, BITCOIN_ANCHOR_TIMEOUT)) { /* Anchor didn't reach blockchain in reasonable time. */ queue_pkt_err(peer, pkt_err(peer, "Anchor timed out")); return next_state(peer, cstatus, STATE_ERR_ANCHOR_TIMEOUT); } else if (input_is(input, BITCOIN_ANCHOR_DEPTHOK)) { queue_pkt_open_complete(peer); if (peer->state == STATE_OPEN_WAITING_THEIRANCHOR_THEYCOMPLETED) { complete_cmd(peer, &cstatus, CMD_SUCCESS); return next_state(peer, cstatus, STATE_NORMAL_LOWPRIO); } return next_state(peer, cstatus, STATE_OPEN_WAIT_FOR_COMPLETE_THEIRANCHOR); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto anchor_unspent; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { /* This should be impossible. */ return next_state(peer, cstatus, STATE_ERR_INFORMATION_LEAK); } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT); complete_cmd(peer, &cstatus, CMD_FAIL); goto them_unilateral; } else if (input_is(input, CMD_CLOSE)) { /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT); complete_cmd(peer, &cstatus, CMD_FAIL); goto start_clearing; } else if (input_is(input, INPUT_CONNECTION_LOST)) { /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT); complete_cmd(peer, &cstatus, CMD_FAIL); goto start_unilateral_close; } else if (input_is(input, PKT_CLOSE_CLEARING)) { /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT); complete_cmd(peer, &cstatus, CMD_FAIL); goto accept_clearing; } else if (input_is_pkt(input)) { /* We no longer care about anchor depth. */ peer_unwatch_anchor_depth(peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT); complete_cmd(peer, &cstatus, CMD_FAIL); goto unexpected_pkt; } break; case STATE_OPEN_WAIT_FOR_COMPLETE_OURANCHOR: case STATE_OPEN_WAIT_FOR_COMPLETE_THEIRANCHOR: if (input_is(input, PKT_OPEN_COMPLETE)) { /* Ready for business! Anchorer goes first. */ if (peer->state == STATE_OPEN_WAIT_FOR_COMPLETE_OURANCHOR) { complete_cmd(peer, &cstatus, CMD_SUCCESS); return next_state(peer, cstatus, STATE_NORMAL_HIGHPRIO); } else { complete_cmd(peer, &cstatus, CMD_SUCCESS); return next_state(peer, cstatus, STATE_NORMAL_LOWPRIO); } } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto anchor_unspent; /* Nobody should be able to spend anchor, except via the * commit txs. */ } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { return next_state(peer, cstatus, STATE_ERR_INFORMATION_LEAK); } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto them_unilateral; } else if (input_is(input, CMD_CLOSE)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto start_clearing; } else if (input_is(input, INPUT_CONNECTION_LOST)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto start_unilateral_close; } else if (input_is(input, PKT_CLOSE_CLEARING)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto accept_clearing; } else if (input_is_pkt(input)) { complete_cmd(peer, &cstatus, CMD_FAIL); goto unexpected_pkt; } break; /* * Channel normal operating states. */ case STATE_NORMAL_LOWPRIO: case STATE_NORMAL_HIGHPRIO: assert(peer->cond == PEER_CMD_OK); if (input_is(input, CMD_SEND_HTLC_ADD)) { /* We are to send an HTLC update. */ queue_pkt_htlc_add(peer, idata->htlc_prog); change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); return next_state(peer, cstatus, prio(peer->state, STATE_WAIT_FOR_HTLC_ACCEPT)); } else if (input_is(input, CMD_SEND_HTLC_FULFILL)) { /* We are to send an HTLC fulfill. */ queue_pkt_htlc_fulfill(peer, idata->htlc_prog); change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); return next_state(peer, cstatus, prio(peer->state, STATE_WAIT_FOR_UPDATE_ACCEPT)); } else if (input_is(input, CMD_SEND_HTLC_FAIL)) { /* We are to send an HTLC fail. */ queue_pkt_htlc_fail(peer, idata->htlc_prog); change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); return next_state(peer, cstatus, prio(peer->state, STATE_WAIT_FOR_UPDATE_ACCEPT)); } else if (input_is(input, CMD_CLOSE)) { goto start_clearing; } else if (input_is(input, INPUT_CONNECTION_LOST)) { goto start_unilateral_close; } else if (input_is(input, PKT_UPDATE_ADD_HTLC)) { change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); goto accept_htlc_add; } else if (input_is(input, PKT_UPDATE_FULFILL_HTLC)) { change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); goto accept_htlc_fulfill; } else if (input_is(input, PKT_UPDATE_FAIL_HTLC)) { change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); goto accept_htlc_fail; } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { goto them_unilateral; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { goto old_commit_spotted; } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { goto anchor_unspent; } else if (input_is(input, PKT_CLOSE_CLEARING)) { goto accept_clearing; } else if (input_is_pkt(input)) { goto unexpected_pkt; } break; case STATE_WAIT_FOR_HTLC_ACCEPT_LOWPRIO: case STATE_WAIT_FOR_HTLC_ACCEPT_HIGHPRIO: /* HTLCs can also evoke a refusal. */ if (input_is(input, PKT_UPDATE_DECLINE_HTLC)) { peer_htlc_declined(peer, idata->pkt); complete_cmd(peer, &cstatus, CMD_FAIL); /* No update means no priority change. */ return next_state(peer, cstatus, prio(peer->state, STATE_NORMAL)); } /* Fall thru */ case STATE_WAIT_FOR_UPDATE_ACCEPT_LOWPRIO: case STATE_WAIT_FOR_UPDATE_ACCEPT_HIGHPRIO: if (input_is(input, PKT_UPDATE_ADD_HTLC)) { /* If we're high priority, ignore their packet */ if (high_priority(peer->state)) return cstatus; /* Otherwise, process their request first: defer ours */ peer_htlc_ours_deferred(peer); complete_cmd(peer, &cstatus, CMD_REQUEUE); /* Stay busy, since we're processing theirs. */ change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); goto accept_htlc_add; } else if (input_is(input, PKT_UPDATE_FULFILL_HTLC)) { /* If we're high priority, ignore their packet */ if (high_priority(peer->state)) return cstatus; /* Otherwise, process their request first: defer ours */ peer_htlc_ours_deferred(peer); complete_cmd(peer, &cstatus, CMD_REQUEUE); /* Stay busy, since we're processing theirs. */ change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); goto accept_htlc_fulfill; } else if (input_is(input, PKT_UPDATE_FAIL_HTLC)) { /* If we're high priority, ignore their packet */ if (high_priority(peer->state)) return cstatus; /* Otherwise, process their request first: defer ours */ peer_htlc_ours_deferred(peer); complete_cmd(peer, &cstatus, CMD_REQUEUE); /* Stay busy, since we're processing theirs. */ change_peer_cond(peer, PEER_CMD_OK, PEER_BUSY); goto accept_htlc_fail; } else if (input_is(input, PKT_UPDATE_ACCEPT)) { err = accept_pkt_update_accept(peer, idata->pkt); if (err) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto err_start_unilateral_close; } queue_pkt_update_signature(peer); /* HTLC is signed (though old tx not revoked yet!) */ return next_state(peer, cstatus, prio(peer->state, STATE_WAIT_FOR_UPDATE_COMPLETE)); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto anchor_unspent; } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto them_unilateral; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto old_commit_spotted; } else if (input_is(input, CMD_CLOSE)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto start_clearing; } else if (input_is(input, INPUT_CONNECTION_LOST)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto start_unilateral_close; } else if (input_is(input, PKT_CLOSE_CLEARING)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto accept_clearing; } else if (input_is_pkt(input)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto unexpected_pkt; } break; case STATE_WAIT_FOR_UPDATE_COMPLETE_LOWPRIO: case STATE_WAIT_FOR_UPDATE_COMPLETE_HIGHPRIO: if (input_is(input, PKT_UPDATE_COMPLETE)) { err = accept_pkt_update_complete(peer, idata->pkt); if (err) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto err_start_unilateral_close; } peer_htlc_done(peer); complete_cmd(peer, &cstatus, CMD_SUCCESS); return next_state(peer, cstatus, toggle_prio(peer->state, STATE_NORMAL)); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto anchor_unspent; } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto them_unilateral; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto old_commit_spotted; } else if (input_is(input, PKT_CLOSE_CLEARING)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto accept_clearing; } else if (input_is(input, CMD_CLOSE)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto start_clearing; } else if (input_is(input, INPUT_CONNECTION_LOST)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto start_unilateral_close; } else if (input_is_pkt(input)) { peer_htlc_aborted(peer); complete_cmd(peer, &cstatus, CMD_FAIL); goto unexpected_pkt; } break; case STATE_WAIT_FOR_UPDATE_SIG_LOWPRIO: case STATE_WAIT_FOR_UPDATE_SIG_HIGHPRIO: if (input_is(input, PKT_UPDATE_SIGNATURE)) { err = accept_pkt_update_signature(peer, idata->pkt); if (err) { peer_htlc_aborted(peer); goto err_start_unilateral_close; } queue_pkt_update_complete(peer); peer_htlc_done(peer); change_peer_cond(peer, PEER_BUSY, PEER_CMD_OK); /* Toggle between high and low priority states. */ return next_state(peer, cstatus, toggle_prio(peer->state, STATE_NORMAL)); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { peer_htlc_aborted(peer); goto anchor_unspent; } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { peer_htlc_aborted(peer); goto them_unilateral; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { peer_htlc_aborted(peer); goto old_commit_spotted; } else if (input_is(input, CMD_CLOSE)) { peer_htlc_aborted(peer); goto start_clearing; } else if (input_is(input, INPUT_CONNECTION_LOST)) { peer_htlc_aborted(peer); goto start_unilateral_close; } else if (input_is(input, PKT_CLOSE_CLEARING)) { peer_htlc_aborted(peer); goto accept_clearing; } else if (input_is_pkt(input)) { peer_htlc_aborted(peer); goto unexpected_pkt; } break; case STATE_US_CLEARING: /* This is their reply once they're clearing too. */ if (input_is(input, PKT_CLOSE_CLEARING)) { err = accept_pkt_close_clearing(peer, idata->pkt); if (err) goto err_start_unilateral_close; /* Notify us when there are no more htlcs in * either commit tx */ peer_watch_htlcs_cleared(peer, INPUT_HTLCS_CLEARED); return next_state(peer, cstatus, STATE_BOTH_CLEARING); /* FIXME: We must continue to allow fulfill & fail! */ } else if (input_is(input, CMD_SEND_HTLC_FAIL) || input_is(input, CMD_SEND_HTLC_FULFILL)) { err = pkt_err(peer, "FIXME: cmd during clearing."); goto err_start_unilateral_close; } else if (input_is(input, INPUT_CONNECTION_LOST)) { goto start_unilateral_close; } else if (input_is_pkt(input)) { /* FIXME: We must continue to allow add, fulfill & fail packets */ goto unexpected_pkt; } break; case STATE_BOTH_CLEARING: if (input_is(input, INPUT_HTLCS_CLEARED)) { goto start_closing_cleared; } else if (input_is(input, CMD_SEND_HTLC_FAIL) || input_is(input, CMD_SEND_HTLC_FULFILL)) { err = pkt_err(peer, "FIXME: cmd during clearing."); goto err_start_unilateral_close; } else if (input_is(input, INPUT_CONNECTION_LOST)) { goto start_unilateral_close; } else if (input_is_pkt(input)) { /* FIXME: We must continue to allow fulfill & fail packets */ goto unexpected_pkt; } break; case STATE_WAIT_FOR_CLOSE_SIG: if (input_is(input, PKT_CLOSE_SIGNATURE)) { bool matches; err = accept_pkt_close_sig(peer, idata->pkt, &matches); if (err) goto err_start_unilateral_close; /* Did they offer the same fee we did? */ if (matches) { peer_unwatch_close_timeout(peer, INPUT_CLOSE_COMPLETE_TIMEOUT); /* Send close TX. */ queue_tx_broadcast(broadcast, bitcoin_close(peer)); change_peer_cond(peer, PEER_CLOSING, PEER_CLOSED); return next_state(peer, cstatus, STATE_CLOSE_WAIT_CLOSE); } /* Offer the new fee. */ queue_pkt_close_signature(peer); return unchanged_state(cstatus); } else if (input_is(input, INPUT_CONNECTION_LOST)) { goto start_unilateral_close; } else if (input_is(input, INPUT_CLOSE_COMPLETE_TIMEOUT)) { err = pkt_err(peer, "Close timed out"); goto err_start_unilateral_close; } else if (input_is_pkt(input)) { goto unexpected_pkt; } break; /* Close states are regular: handle as a group. */ case STATE_CLOSE_WAIT_HTLCS: case STATE_CLOSE_WAIT_STEAL: case STATE_CLOSE_WAIT_SPENDTHEM: case STATE_CLOSE_WAIT_SPENDTHEM_WITH_HTLCS: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_WITH_HTLCS: case STATE_CLOSE_WAIT_CLOSE: case STATE_CLOSE_WAIT_STEAL_CLOSE: case STATE_CLOSE_WAIT_SPENDTHEM_CLOSE: case STATE_CLOSE_WAIT_SPENDTHEM_CLOSE_WITH_HTLCS: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_CLOSE: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_CLOSE_WITH_HTLCS: case STATE_CLOSE_WAIT_STEAL_OURCOMMIT: case STATE_CLOSE_WAIT_STEAL_OURCOMMIT_WITH_HTLCS: case STATE_CLOSE_WAIT_SPENDTHEM_OURCOMMIT: case STATE_CLOSE_WAIT_SPENDTHEM_OURCOMMIT_WITH_HTLCS: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_OURCOMMIT: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_OURCOMMIT_WITH_HTLCS: case STATE_CLOSE_WAIT_CLOSE_OURCOMMIT: case STATE_CLOSE_WAIT_STEAL_CLOSE_OURCOMMIT: case STATE_CLOSE_WAIT_SPENDTHEM_CLOSE_OURCOMMIT: case STATE_CLOSE_WAIT_SPENDTHEM_CLOSE_OURCOMMIT_WITH_HTLCS: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_CLOSE_OURCOMMIT: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_CLOSE_OURCOMMIT_WITH_HTLCS: case STATE_CLOSE_WAIT_STEAL_SPENDOURS: case STATE_CLOSE_WAIT_STEAL_SPENDOURS_WITH_HTLCS: case STATE_CLOSE_WAIT_SPENDTHEM_SPENDOURS: case STATE_CLOSE_WAIT_SPENDTHEM_SPENDOURS_WITH_HTLCS: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_SPENDOURS: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_SPENDOURS_WITH_HTLCS: case STATE_CLOSE_WAIT_CLOSE_SPENDOURS: case STATE_CLOSE_WAIT_STEAL_CLOSE_SPENDOURS: case STATE_CLOSE_WAIT_SPENDTHEM_CLOSE_SPENDOURS: case STATE_CLOSE_WAIT_SPENDTHEM_CLOSE_SPENDOURS_WITH_HTLCS: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_CLOSE_SPENDOURS: case STATE_CLOSE_WAIT_STEAL_SPENDTHEM_CLOSE_SPENDOURS_WITH_HTLCS: case STATE_CLOSE_WAIT_OURCOMMIT: case STATE_CLOSE_WAIT_OURCOMMIT_WITH_HTLCS: case STATE_CLOSE_WAIT_SPENDOURS: case STATE_CLOSE_WAIT_SPENDOURS_WITH_HTLCS: { unsigned int bits; enum state_input closed; bits = STATE_TO_BITS(peer->state); /* Once we see a steal or spend completely buried, we * close unless we're still waiting for htlcs*/ if (bits & STATE_CLOSE_HTLCS_BIT) closed = STATE_CLOSE_WAIT_HTLCS; else closed = STATE_CLOSED; if ((bits & STATE_CLOSE_STEAL_BIT) && input_is(input, BITCOIN_STEAL_DONE)) { /* One a steal is complete, we don't care about htlcs * (we stole them all) */ if (bits & STATE_CLOSE_HTLCS_BIT) peer_unwatch_all_htlc_outputs(peer); return next_state(peer, cstatus, STATE_CLOSED); } if ((bits & STATE_CLOSE_SPENDTHEM_BIT) && input_is(input, BITCOIN_SPEND_THEIRS_DONE)) { BUILD_ASSERT(!(STATE_TO_BITS(STATE_CLOSE_WAIT_HTLCS) & STATE_CLOSE_SPENDTHEM_BIT)); return next_state(peer, cstatus, closed); } if ((bits & STATE_CLOSE_CLOSE_BIT) && input_is(input, BITCOIN_CLOSE_DONE)) { BUILD_ASSERT(!(STATE_TO_BITS(STATE_CLOSE_WAIT_HTLCS) & STATE_CLOSE_CLOSE_BIT)); return next_state(peer, cstatus, closed); } if ((bits & STATE_CLOSE_OURCOMMIT_BIT) && input_is(input, BITCOIN_ANCHOR_OURCOMMIT_DELAYPASSED)) { BUILD_ASSERT(!(STATE_TO_BITS(STATE_CLOSE_WAIT_HTLCS) & STATE_CLOSE_OURCOMMIT_BIT)); tx = bitcoin_spend_ours(peer); /* Now we need to wait for our commit to be done. */ queue_tx_broadcast(broadcast, tx); peer_watch_tx(peer, tx, BITCOIN_SPEND_OURS_DONE); bits &= ~STATE_CLOSE_OURCOMMIT_BIT; bits |= STATE_CLOSE_SPENDOURS_BIT; return next_state(peer, cstatus, BITS_TO_STATE(bits)); } if ((bits & STATE_CLOSE_SPENDOURS_BIT) && input_is(input, BITCOIN_SPEND_OURS_DONE)) { BUILD_ASSERT(!(STATE_TO_BITS(STATE_CLOSE_WAIT_HTLCS) & STATE_CLOSE_SPENDOURS_BIT)); return next_state(peer, cstatus, closed); } /* If we have htlcs, we can get other inputs... */ if (bits & STATE_CLOSE_HTLCS_BIT) { if (input_is(input, INPUT_NO_MORE_HTLCS)) { /* Clear bit, might lead to STATE_CLOSED. */ BUILD_ASSERT((BITS_TO_STATE(STATE_TO_BITS(STATE_CLOSE_WAIT_HTLCS) & ~STATE_CLOSE_HTLCS_BIT)) == STATE_CLOSED); bits &= ~STATE_CLOSE_HTLCS_BIT; return next_state(peer, cstatus, BITS_TO_STATE(bits)); } else if (input_is(input, BITCOIN_HTLC_TOTHEM_SPENT)) { const struct htlc *htlc; /* They revealed R value. */ htlc = peer_tx_revealed_r_value(peer, idata->btc); /* We don't care any more. */ peer_unwatch_htlc_output(peer, htlc, INPUT_NO_MORE_HTLCS); return unchanged_state(cstatus); } else if (input_is(input, BITCOIN_HTLC_TOTHEM_TIMEOUT)){ tx = bitcoin_htlc_timeout(peer, idata->htlc); /* HTLC timed out, spend it back to us. */ queue_tx_broadcast(broadcast, tx); /* Don't unwatch yet; they could yet * try to spend, revealing rvalue. */ /* We're done when that gets buried. */ peer_watch_htlc_spend(peer, tx, idata->htlc, BITCOIN_HTLC_RETURN_SPEND_DONE); return unchanged_state(cstatus); } else if (input_is(input, INPUT_RVALUE)) { tx = bitcoin_htlc_spend(peer, idata->htlc); /* Spend it... */ queue_tx_broadcast(broadcast, tx); /* We're done when it gets buried. */ peer_watch_htlc_spend(peer, tx, idata->htlc, BITCOIN_HTLC_FULFILL_SPEND_DONE); /* Don't care about this one any more. */ peer_unwatch_htlc_output(peer, idata->htlc, INPUT_NO_MORE_HTLCS); return unchanged_state(cstatus); } else if (input_is(input, BITCOIN_HTLC_FULFILL_SPEND_DONE)) { /* Stop watching spend, send * INPUT_NO_MORE_HTLCS when done. */ peer_unwatch_htlc_spend(peer, idata->htlc, INPUT_NO_MORE_HTLCS); return unchanged_state(cstatus); } else if (input_is(input, BITCOIN_HTLC_RETURN_SPEND_DONE)) { /* Stop watching spend, send * INPUT_NO_MORE_HTLCS when done. */ peer_unwatch_htlc_spend(peer, idata->htlc, INPUT_NO_MORE_HTLCS); /* Don't need to watch the HTLC output any more, * either. */ peer_unwatch_htlc_output(peer, idata->htlc, INPUT_NO_MORE_HTLCS); return unchanged_state(cstatus); } else if (input_is(input, BITCOIN_HTLC_TOUS_TIMEOUT)) { /* They can spend, we no longer care * about this HTLC. */ peer_unwatch_htlc_output(peer, idata->htlc, INPUT_NO_MORE_HTLCS); return unchanged_state(cstatus); } } /* If we're just waiting for HTLCs, anything else is an error */ if (peer->state == STATE_CLOSE_WAIT_HTLCS) break; /* * Now, other side can always spring a commit transaction on us * (even if they already have, due to tx malleability). */ if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { tx = bitcoin_spend_theirs(peer, idata->btc); queue_tx_broadcast(broadcast, tx); peer_watch_tx(peer, tx, BITCOIN_SPEND_THEIRS_DONE); /* HTLC watches: if any, set HTLCs bit. */ if (peer_watch_their_htlc_outputs(peer, idata->btc, BITCOIN_HTLC_TOUS_TIMEOUT, BITCOIN_HTLC_TOTHEM_SPENT, BITCOIN_HTLC_TOTHEM_TIMEOUT)) bits |= STATE_CLOSE_HTLCS_BIT; bits |= STATE_CLOSE_SPENDTHEM_BIT; return next_state_bits(peer, cstatus, bits); /* This can happen multiple times: need to steal ALL */ } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { tx = bitcoin_steal(peer, idata->btc); if (!tx) return next_state(peer, cstatus, STATE_ERR_INFORMATION_LEAK); queue_tx_broadcast(broadcast, tx); peer_watch_tx(peer, tx, BITCOIN_STEAL_DONE); bits |= STATE_CLOSE_STEAL_BIT; return next_state_bits(peer, cstatus, bits); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) goto anchor_unspent; break; } /* Should never happen. */ case STATE_ERR_INTERNAL: case STATE_ERR_INFORMATION_LEAK: case STATE_ERR_ANCHOR_TIMEOUT: case STATE_ERR_ANCHOR_LOST: case STATE_CLOSED: case STATE_MAX: case STATE_UNUSED_CLOSE_WAIT_STEAL_WITH_HTLCS: case STATE_UNUSED_CLOSE_WAIT_CLOSE_WITH_HTLCS: case STATE_UNUSED_CLOSE_WAIT_STEAL_CLOSE_WITH_HTLCS: case STATE_UNUSED_CLOSE_WAIT_CLOSE_OURCOMMIT_WITH_HTLCS: case STATE_UNUSED_CLOSE_WAIT_STEAL_CLOSE_OURCOMMIT_WITH_HTLCS: case STATE_UNUSED_CLOSE_WAIT_CLOSE_SPENDOURS_WITH_HTLCS: case STATE_UNUSED_CLOSE_WAIT_STEAL_CLOSE_SPENDOURS_WITH_HTLCS: return next_state(peer, cstatus, STATE_ERR_INTERNAL); } /* State machine should handle all possible states. */ return next_state(peer, cstatus, STATE_ERR_INTERNAL); unexpected_pkt: /* * We got a weird packet, so we need to close unilaterally. */ peer_unexpected_pkt(peer, idata->pkt); /* Don't reply to an error with an error. */ if (input_is(input, PKT_ERROR)) { goto start_unilateral_close; } err = pkt_err_unexpected(peer, idata->pkt); goto err_start_unilateral_close; unexpected_pkt_nocleanup: /* * Unexpected packet, but nothing sent to chain yet, so no cleanup. */ /* Don't reply to an error with an error. */ if (input_is(input, PKT_ERROR)) { goto close_nocleanup; } err = pkt_err_unexpected(peer, idata->pkt); goto err_close_nocleanup; anchor_unspent: /* * Bitcoind tells us anchor got double-spent. If we double-spent it * then we're malfunctioning. If they double-spent it, then they * managed to cheat us: post_to_reddit(); */ return next_state(peer, cstatus, STATE_ERR_ANCHOR_LOST); err_close_nocleanup: /* * Something went wrong, but we haven't sent anything to the blockchain * so there's nothing to clean up. */ queue_pkt_err(peer, err); close_nocleanup: change_peer_cond(peer, PEER_CMD_OK, PEER_CLOSED); return next_state(peer, cstatus, STATE_CLOSED); err_start_unilateral_close: /* * They timed out, or were broken; we are going to close unilaterally. */ queue_pkt_err(peer, err); start_unilateral_close: /* * Close unilaterally. */ /* No more inputs, no more commands. */ set_peer_cond(peer, PEER_CLOSED); /* * If they sent us a close tx, that's always cheaper than * broadcasting our last commit tx, and our funds are not * timelocked. */ if (peer_has_close_sig(peer)) { queue_tx_broadcast(broadcast, bitcoin_close(peer)); return next_state(peer, cstatus, STATE_CLOSE_WAIT_CLOSE); } tx = bitcoin_commit(peer); queue_tx_broadcast(broadcast, tx); peer_watch_delayed(peer, tx, BITCOIN_ANCHOR_OURCOMMIT_DELAYPASSED); /* HTLC watches. */ if (peer_watch_our_htlc_outputs(peer, tx, BITCOIN_HTLC_TOUS_TIMEOUT, BITCOIN_HTLC_TOTHEM_SPENT, BITCOIN_HTLC_TOTHEM_TIMEOUT)) return next_state(peer, cstatus, STATE_CLOSE_WAIT_OURCOMMIT_WITH_HTLCS); return next_state(peer, cstatus, STATE_CLOSE_WAIT_OURCOMMIT); them_unilateral: assert(input == BITCOIN_ANCHOR_THEIRSPEND); /* * Bitcoind tells us they did unilateral close. */ queue_pkt_err(peer, pkt_err(peer, "Commit tx noticed")); /* No more inputs, no more commands. */ set_peer_cond(peer, PEER_CLOSED); tx = bitcoin_spend_theirs(peer, idata->btc); queue_tx_broadcast(broadcast, tx); peer_watch_tx(peer, tx, BITCOIN_SPEND_THEIRS_DONE); /* HTLC watches (based on what they broadcast, which *may* be out * of step with our current state by +/- 1 htlc. */ if (peer_watch_their_htlc_outputs(peer, idata->btc, BITCOIN_HTLC_TOUS_TIMEOUT, BITCOIN_HTLC_TOTHEM_SPENT, BITCOIN_HTLC_TOTHEM_TIMEOUT)) return next_state(peer, cstatus, STATE_CLOSE_WAIT_SPENDTHEM_WITH_HTLCS); return next_state(peer, cstatus, STATE_CLOSE_WAIT_SPENDTHEM); accept_htlc_add: err = accept_pkt_htlc_add(peer, idata->pkt, &decline); if (err) goto err_start_unilateral_close; if (decline) { queue_pkt_err(peer, decline); peer_htlc_declined(peer, decline); /* No update means no priority change. */ change_peer_cond(peer, PEER_BUSY, PEER_CMD_OK); /* We may already be in STATE_NORMAL */ return next_state_nocheck(peer, cstatus, prio(peer->state, STATE_NORMAL)); } queue_pkt_update_accept(peer); return next_state(peer, cstatus, prio(peer->state, STATE_WAIT_FOR_UPDATE_SIG)); accept_htlc_fail: err = accept_pkt_htlc_fail(peer, idata->pkt); if (err) goto err_start_unilateral_close; queue_pkt_update_accept(peer); return next_state(peer, cstatus, prio(peer->state, STATE_WAIT_FOR_UPDATE_SIG)); accept_htlc_fulfill: err = accept_pkt_htlc_fulfill(peer, idata->pkt); if (err) goto err_start_unilateral_close; queue_pkt_update_accept(peer); return next_state(peer, cstatus, prio(peer->state, STATE_WAIT_FOR_UPDATE_SIG)); start_clearing: /* * Start a mutual close: tell them we want to clear. */ queue_pkt_close_clearing(peer); /* No more commands, we're already closing. */ set_peer_cond(peer, PEER_CLOSING); return next_state(peer, cstatus, STATE_US_CLEARING); start_closing_cleared: /* As soon as we send packet, they could close. */ peer_calculate_close_fee(peer); peer_watch_close(peer, BITCOIN_CLOSE_DONE, INPUT_CLOSE_COMPLETE_TIMEOUT); queue_pkt_close_signature(peer); return next_state(peer, cstatus, STATE_WAIT_FOR_CLOSE_SIG); accept_clearing: err = accept_pkt_close_clearing(peer, idata->pkt); if (err) goto err_start_unilateral_close; /* Notify us when there are no more htlcs in either commit tx */ peer_watch_htlcs_cleared(peer, INPUT_HTLCS_CLEARED); /* No more commands, we're already closing. */ set_peer_cond(peer, PEER_CLOSING); /* Tell them we're clearing too. */ queue_pkt_close_clearing(peer); return next_state(peer, cstatus, STATE_BOTH_CLEARING); instant_close: /* * Closing, but we haven't sent anything to the blockchain so * there's nothing to clean up. */ /* FIXME: Should we tell other side we're going? */ set_peer_cond(peer, PEER_CLOSED); /* We can't have any HTLCs, since we haven't started. */ if (committed_to_htlcs(peer)) return next_state(peer, cstatus, STATE_ERR_INTERNAL); return next_state(peer, cstatus, STATE_CLOSED); old_commit_spotted: /* * bitcoind reported a broadcast of the not-latest commit tx. */ queue_pkt_err(peer, pkt_err(peer, "Otherspend noticed")); /* No more packets, no more commands. */ set_peer_cond(peer, PEER_CLOSED); /* If we can't find it, we're lost. */ tx = bitcoin_steal(peer, idata->btc); if (!tx) return next_state(peer, cstatus, STATE_ERR_INFORMATION_LEAK); queue_tx_broadcast(broadcast, tx); peer_watch_tx(peer, tx, BITCOIN_STEAL_DONE); return next_state(peer, cstatus, STATE_CLOSE_WAIT_STEAL); }