#include #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) #define add_effect(e, field, val) \ do { \ struct state_effect *_e = tal(ctx, struct state_effect); \ _e->etype = STATE_EFFECT_##field; \ _e->u.field = (val); \ _e->next = (*e); \ (*e) = _e; \ } while(0) /* 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) static struct state_effect *next_state(const tal_t *ctx, struct state_effect *effect, const enum state state) { add_effect(&effect, new_state, state); return effect; } struct state_effect *state(const tal_t *ctx, const enum state state, const struct peer *peer, const enum state_input input, const union input *idata) { struct state_effect *effect = NULL; Pkt *decline; struct bitcoin_tx *tx; Pkt *err; struct htlc_watch *htlcs; struct htlc_progress *htlcprog; switch (state) { /* * Initial channel opening states. */ case STATE_INIT_NOANCHOR: assert(input == INPUT_NONE); add_effect(&effect, send_pkt, pkt_open(ctx, peer, OPEN_CHANNEL__ANCHOR_OFFER__WONT_CREATE_ANCHOR)); return next_state(ctx, effect, STATE_OPEN_WAIT_FOR_OPEN_NOANCHOR); case STATE_INIT_WITHANCHOR: assert(input == INPUT_NONE); add_effect(&effect, send_pkt, pkt_open(ctx, peer, OPEN_CHANNEL__ANCHOR_OFFER__WILL_CREATE_ANCHOR)); return next_state(ctx, effect, STATE_OPEN_WAIT_FOR_OPEN_WITHANCHOR); case STATE_OPEN_WAIT_FOR_OPEN_NOANCHOR: if (input_is(input, PKT_OPEN)) { err = accept_pkt_open(ctx, peer, idata->pkt, &effect); if (err) goto err_close_nocleanup; return next_state(ctx, effect, STATE_OPEN_WAIT_FOR_ANCHOR); } else if (input_is(input, CMD_SEND_HTLC_UPDATE)) { /* Can't do this until we're open. */ add_effect(&effect, cmd_defer, input); /* No state change. */ return effect; } else if (input_is(input, CMD_CLOSE)) { goto instant_close; } else if (input_is_pkt(input)) { goto unexpected_pkt_nocleanup; } break; case STATE_OPEN_WAIT_FOR_OPEN_WITHANCHOR: if (input_is(input, PKT_OPEN)) { err = accept_pkt_open(ctx, peer, idata->pkt, &effect); if (err) goto err_close_nocleanup; add_effect(&effect, send_pkt, pkt_anchor(ctx, peer)); return next_state(ctx, effect, STATE_OPEN_WAIT_FOR_COMMIT_SIG); } else if (input_is(input, CMD_SEND_HTLC_UPDATE)) { /* Can't do this until we're open. */ add_effect(&effect, cmd_defer, input); /* No state change. */ return effect; } else if (input_is(input, CMD_CLOSE)) { goto instant_close; } else if (input_is_pkt(input)) { goto unexpected_pkt_nocleanup; } break; case STATE_OPEN_WAIT_FOR_ANCHOR: if (input_is(input, PKT_OPEN_ANCHOR)) { err = accept_pkt_anchor(ctx, peer, idata->pkt, &effect); if (err) goto err_close_nocleanup; add_effect(&effect, send_pkt, pkt_open_commit_sig(ctx, peer)); add_effect(&effect, watch, bitcoin_watch_anchor(ctx, peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT, BITCOIN_ANCHOR_UNSPENT, BITCOIN_ANCHOR_THEIRSPEND, BITCOIN_ANCHOR_OTHERSPEND)); return next_state(ctx, effect, STATE_OPEN_WAITING_THEIRANCHOR); } else if (input_is(input, CMD_SEND_HTLC_UPDATE)) { /* Can't do this until we're open. */ add_effect(&effect, cmd_defer, input); /* No state change. */ return effect; } else if (input_is(input, CMD_CLOSE)) { goto instant_close; } else if (input_is_pkt(input)) { 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(ctx, peer, idata->pkt, &effect); if (err) goto err_start_unilateral_close; add_effect(&effect, broadcast_tx, bitcoin_anchor(ctx, peer)); add_effect(&effect, watch, bitcoin_watch_anchor(ctx, peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE, BITCOIN_ANCHOR_UNSPENT, BITCOIN_ANCHOR_THEIRSPEND, BITCOIN_ANCHOR_OTHERSPEND)); return next_state(ctx, effect, STATE_OPEN_WAITING_OURANCHOR); } else if (input_is(input, CMD_SEND_HTLC_UPDATE)) { /* Can't do this until we're open. */ add_effect(&effect, cmd_defer, input); /* No state change. */ return effect; } else if (input_is(input, CMD_CLOSE)) { goto instant_close; } else if (input_is_pkt(input)) { goto unexpected_pkt_nocleanup; } break; case STATE_OPEN_WAITING_OURANCHOR: if (input_is(input, BITCOIN_ANCHOR_DEPTHOK)) { add_effect(&effect, send_pkt, pkt_open_complete(ctx, peer)); return next_state(ctx, effect, STATE_OPEN_WAIT_FOR_COMPLETE_OURANCHOR); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { goto anchor_unspent; } else if (input_is(input, PKT_OPEN_COMPLETE)) { /* Ignore until we've hit depth ourselves. */ add_effect(&effect, cmd_defer, input); /* No state change. */ return effect; } else if (input_is(input, CMD_SEND_HTLC_UPDATE)) { /* Can't do this until we're open. */ add_effect(&effect, cmd_defer, input); /* No state change. */ return effect; } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { /* We no longer care about anchor depth. */ add_effect(&effect, unwatch, bitcoin_unwatch_anchor_depth(ctx, peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE)); goto them_unilateral; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { /* This should be impossible. */ return next_state(ctx, effect, STATE_ERR_INFORMATION_LEAK); } else if (input_is(input, CMD_CLOSE)) { /* We no longer care about anchor depth. */ add_effect(&effect, unwatch, bitcoin_unwatch_anchor_depth(ctx, peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE)); goto start_closing; } else if (input_is(input, PKT_CLOSE)) { /* We no longer care about anchor depth. */ add_effect(&effect, unwatch, bitcoin_unwatch_anchor_depth(ctx, peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE)); goto accept_closing; } else if (input_is_pkt(input)) { /* We no longer care about anchor depth. */ add_effect(&effect, unwatch, bitcoin_unwatch_anchor_depth(ctx, peer, BITCOIN_ANCHOR_DEPTHOK, INPUT_NONE)); goto unexpected_pkt; } break; case STATE_OPEN_WAITING_THEIRANCHOR: if (input_is(input, BITCOIN_ANCHOR_TIMEOUT)) { /* Anchor didn't reach blockchain in reasonable time. */ add_effect(&effect, send_pkt, pkt_err(ctx, "Anchor timed out")); return next_state(ctx, effect, STATE_ERR_ANCHOR_TIMEOUT); } else if (input_is(input, BITCOIN_ANCHOR_DEPTHOK)) { add_effect(&effect, send_pkt, pkt_open_complete(ctx, peer)); return next_state(ctx, effect, STATE_OPEN_WAIT_FOR_COMPLETE_THEIRANCHOR); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { goto anchor_unspent; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { /* This should be impossible. */ return next_state(ctx, effect, STATE_ERR_INFORMATION_LEAK); } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { /* We no longer care about anchor depth. */ add_effect(&effect, unwatch, bitcoin_unwatch_anchor_depth(ctx, peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT)); goto them_unilateral; } else if (input_is(input, PKT_OPEN_COMPLETE)) { /* Ignore until we've hit depth ourselves. */ add_effect(&effect, cmd_defer, input); /* No state change. */ return effect; } else if (input_is(input, CMD_SEND_HTLC_UPDATE)) { /* Can't do this until we're open. */ add_effect(&effect, cmd_defer, input); /* No state change. */ return effect; } else if (input_is(input, CMD_CLOSE)) { /* We no longer care about anchor depth. */ add_effect(&effect, unwatch, bitcoin_unwatch_anchor_depth(ctx, peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT)); goto start_closing; } else if (input_is(input, PKT_CLOSE)) { /* We no longer care about anchor depth. */ add_effect(&effect, unwatch, bitcoin_unwatch_anchor_depth(ctx, peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT)); goto accept_closing; } else if (input_is_pkt(input)) { /* We no longer care about anchor depth. */ add_effect(&effect, unwatch, bitcoin_unwatch_anchor_depth(ctx, peer, BITCOIN_ANCHOR_DEPTHOK, BITCOIN_ANCHOR_TIMEOUT)); 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 (state == STATE_OPEN_WAIT_FOR_COMPLETE_OURANCHOR) return next_state(ctx, effect, STATE_NORMAL_HIGHPRIO); else return next_state(ctx, effect, STATE_NORMAL_LOWPRIO); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { 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(ctx, effect, STATE_ERR_INFORMATION_LEAK); } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { goto them_unilateral; } else if (input_is(input, PKT_OPEN_COMPLETE)) { /* Ready for business! */ return next_state(ctx, effect, STATE_NORMAL_HIGHPRIO); } else if (input_is(input, CMD_SEND_HTLC_UPDATE)) { /* Can't do this until we're open. */ add_effect(&effect, cmd_defer, input); /* No state change. */ return effect; } else if (input_is(input, CMD_CLOSE)) { goto start_closing; } else if (input_is(input, PKT_CLOSE)) { goto accept_closing; } else if (input_is_pkt(input)) { goto unexpected_pkt; } break; /* * Channel normal operating states. */ case STATE_NORMAL_LOWPRIO: case STATE_NORMAL_HIGHPRIO: if (input_is(input, CMD_SEND_HTLC_UPDATE)) { /* We are to send an HTLC update. */ add_effect(&effect, send_pkt, pkt_htlc_update(ctx, peer, idata->htlc_prog)); add_effect(&effect, htlc_in_progress, idata->htlc_prog); return next_state(ctx, effect, prio(state, STATE_WAIT_FOR_HTLC_ACCEPT)); } else if (input_is(input, CMD_SEND_HTLC_FULFILL)) { /* We are to send an HTLC fulfill. */ /* This gives us the r value (FIXME: type!) */ add_effect(&effect, r_value, r_value_from_cmd(ctx, peer, idata->htlc)); add_effect(&effect, send_pkt, pkt_htlc_fulfill(ctx, peer, idata->htlc_prog)); add_effect(&effect, htlc_in_progress, idata->htlc_prog); return next_state(ctx, effect, prio(state, STATE_WAIT_FOR_UPDATE_ACCEPT)); } else if (input_is(input, CMD_SEND_HTLC_TIMEDOUT)) { /* We are to send an HTLC timedout. */ add_effect(&effect, send_pkt, pkt_htlc_timedout(ctx, peer, idata->htlc_prog)); add_effect(&effect, htlc_in_progress, idata->htlc_prog); return next_state(ctx, effect, prio(state, STATE_WAIT_FOR_UPDATE_ACCEPT)); } else if (input_is(input, CMD_SEND_HTLC_ROUTEFAIL)) { /* We are to send an HTLC routefail. */ add_effect(&effect, send_pkt, pkt_htlc_routefail(ctx, peer, idata->htlc_prog)); add_effect(&effect, htlc_in_progress, idata->htlc_prog); return next_state(ctx, effect, prio(state, STATE_WAIT_FOR_UPDATE_ACCEPT)); } else if (input_is(input, CMD_CLOSE)) { goto start_closing; } else if (input_is(input, PKT_UPDATE_ADD_HTLC)) { goto accept_htlc_update; } else if (input_is(input, PKT_UPDATE_FULFILL_HTLC)) { goto accept_htlc_fulfill; } else if (input_is(input, PKT_UPDATE_TIMEDOUT_HTLC)) { goto accept_htlc_timedout; } else if (input_is(input, PKT_UPDATE_ROUTEFAIL_HTLC)) { goto accept_htlc_routefail; } 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)) { goto accept_closing; } 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)) { add_effect(&effect, cmd_fail, idata->pkt); add_effect(&effect, htlc_abandon, true); /* No update means no priority change. */ return next_state(ctx, effect, prio(state, STATE_NORMAL)); /* They can't close with an HTLC, so only possible here */ } else if (input_is(input, PKT_CLOSE)) { add_effect(&effect, cmd_fail, NULL); add_effect(&effect, htlc_abandon, true); goto accept_closing; } /* 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(state)) return effect; /* Otherwise, process their request first: defer ours */ add_effect(&effect, cmd_requeue, CMD_SEND_UPDATE_ANY); add_effect(&effect, htlc_abandon, true); goto accept_htlc_update; } else if (input_is(input, PKT_UPDATE_FULFILL_HTLC)) { /* If we're high priority, ignore their packet */ if (high_priority(state)) return effect; /* Otherwise, process their request first: defer ours */ add_effect(&effect, cmd_requeue, CMD_SEND_UPDATE_ANY); add_effect(&effect, htlc_abandon, true); goto accept_htlc_fulfill; } else if (input_is(input, PKT_UPDATE_TIMEDOUT_HTLC)) { /* If we're high priority, ignore their packet */ if (high_priority(state)) return effect; /* Otherwise, process their request first: defer ours */ add_effect(&effect, cmd_requeue, CMD_SEND_UPDATE_ANY); add_effect(&effect, htlc_abandon, true); goto accept_htlc_timedout; } else if (input_is(input, PKT_UPDATE_ROUTEFAIL_HTLC)) { /* If we're high priority, ignore their packet */ if (high_priority(state)) return effect; /* Otherwise, process their request first: defer ours */ add_effect(&effect, cmd_requeue, CMD_SEND_UPDATE_ANY); add_effect(&effect, htlc_abandon, true); goto accept_htlc_routefail; } else if (input_is(input, PKT_UPDATE_ACCEPT)) { struct signature *sig; err = accept_pkt_update_accept(ctx, peer, idata->pkt, &sig, &effect); if (err) { add_effect(&effect, cmd_fail, NULL); add_effect(&effect, htlc_abandon, true); goto err_start_unilateral_close; } add_effect(&effect, update_theirsig, sig); add_effect(&effect, send_pkt, pkt_update_signature(ctx, peer)); /* HTLC is signed (though old tx not revoked yet!) */ add_effect(&effect, htlc_fulfill, true); return next_state(ctx, effect, prio(state, STATE_WAIT_FOR_UPDATE_COMPLETE)); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { add_effect(&effect, cmd_fail, NULL); add_effect(&effect, htlc_abandon, true); goto anchor_unspent; } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { add_effect(&effect, cmd_fail, NULL); add_effect(&effect, htlc_abandon, true); goto them_unilateral; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { add_effect(&effect, cmd_fail, NULL); add_effect(&effect, htlc_abandon, true); goto old_commit_spotted; } else if (input_is(input, CMD_CLOSE)) { add_effect(&effect, cmd_fail, NULL); add_effect(&effect, htlc_abandon, true); goto start_closing; } else if (input_is_pkt(input)) { add_effect(&effect, cmd_fail, NULL); add_effect(&effect, htlc_abandon, true); 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(ctx, peer, idata->pkt, &effect); if (err) { add_effect(&effect, cmd_fail, NULL); goto err_start_unilateral_close; } add_effect(&effect, cmd_success, CMD_SEND_UPDATE_ANY); return next_state(ctx, effect, toggle_prio(state, STATE_NORMAL)); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { add_effect(&effect, cmd_fail, NULL); goto anchor_unspent; } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { add_effect(&effect, cmd_fail, NULL); goto them_unilateral; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { add_effect(&effect, cmd_fail, NULL); goto old_commit_spotted; } else if (input_is(input, PKT_CLOSE)) { add_effect(&effect, cmd_fail, NULL); goto accept_closing; } else if (input_is(input, CMD_CLOSE)) { add_effect(&effect, cmd_fail, NULL); goto start_closing; } else if (input_is_pkt(input)) { add_effect(&effect, cmd_fail, NULL); 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)) { struct signature *sig; err = accept_pkt_update_signature(ctx, peer, idata->pkt, &sig, &effect); if (err) { add_effect(&effect, htlc_abandon, true); goto err_start_unilateral_close; } add_effect(&effect, update_theirsig, sig); add_effect(&effect, send_pkt, pkt_update_complete(ctx, peer)); add_effect(&effect, htlc_fulfill, true); /* Toggle between high and low priority states. */ return next_state(ctx, effect, toggle_prio(state, STATE_NORMAL)); } else if (input_is(input, CMD_SEND_UPDATE_ANY)) { add_effect(&effect, cmd_defer, input); return effect; } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { add_effect(&effect, htlc_abandon, true); goto anchor_unspent; } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { add_effect(&effect, htlc_abandon, true); goto them_unilateral; } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { add_effect(&effect, htlc_abandon, true); goto old_commit_spotted; } else if (input_is(input, CMD_CLOSE)) { add_effect(&effect, htlc_abandon, true); goto start_closing; } else if (input_is(input, PKT_CLOSE)) { add_effect(&effect, htlc_abandon, true); goto accept_closing; } else if (input_is_pkt(input)) { add_effect(&effect, htlc_abandon, true); goto unexpected_pkt; } break; case STATE_WAIT_FOR_CLOSE_COMPLETE: if (input_is(input, PKT_CLOSE_COMPLETE)) { err = accept_pkt_close_complete(ctx, peer, idata->pkt, &effect); if (err) goto err_start_unilateral_close_already_closing; add_effect(&effect, cmd_close_done, true); add_effect(&effect, send_pkt, pkt_close_ack(ctx, peer)); add_effect(&effect, broadcast_tx, bitcoin_close(ctx, peer)); add_effect(&effect, stop_commands, true); add_effect(&effect, stop_packets, true); return next_state(ctx, effect, STATE_CLOSE_WAIT_CLOSE); } else if (input_is(input, PKT_CLOSE)) { /* We can use the sig just like CLOSE_COMPLETE */ err = accept_pkt_simultaneous_close(ctx, peer, idata->pkt, &effect); if (err) goto err_start_unilateral_close_already_closing; add_effect(&effect, cmd_close_done, true); add_effect(&effect, send_pkt, pkt_close_ack(ctx, peer)); add_effect(&effect, broadcast_tx, bitcoin_close(ctx, peer)); add_effect(&effect, stop_commands, true); add_effect(&effect, stop_packets, true); return next_state(ctx, effect, STATE_CLOSE_WAIT_CLOSE); } else if (input_is(input, PKT_ERROR)) { add_effect(&effect, in_error, tal_steal(ctx, idata->pkt)); goto start_unilateral_close_already_closing; } else if (input_is_pkt(input)) { /* We ignore all other packets while closing. */ return next_state(ctx, effect, STATE_WAIT_FOR_CLOSE_COMPLETE); } else if (input_is(input, INPUT_CLOSE_COMPLETE_TIMEOUT)) { /* They didn't respond in time. Unilateral close. */ err = pkt_err(ctx, "Close timed out"); goto err_start_unilateral_close_already_closing; } add_effect(&effect, cmd_close_done, false); add_effect(&effect, stop_commands, true); goto fail_during_close; case STATE_WAIT_FOR_CLOSE_ACK: if (input_is(input, PKT_CLOSE_ACK)) { err = accept_pkt_close_ack(ctx, peer, idata->pkt, &effect); if (err) add_effect(&effect, send_pkt, err); add_effect(&effect, stop_packets, true); /* Just wait for close to happen now. */ return next_state(ctx, effect, STATE_CLOSE_WAIT_CLOSE); } else if (input_is_pkt(input)) { if (input_is(input, PKT_ERROR)) { add_effect(&effect, in_error, tal_steal(ctx, idata->pkt)); } else { add_effect(&effect, send_pkt, unexpected_pkt(ctx, input)); } add_effect(&effect, stop_packets, true); /* Just wait for close to happen now. */ return next_state(ctx, effect, STATE_CLOSE_WAIT_CLOSE); } else if (input_is(input, BITCOIN_CLOSE_DONE)) { /* They didn't ack, but we're closed, so stop. */ add_effect(&effect, stop_packets, true); return next_state(ctx, effect, STATE_CLOSED); } goto fail_during_close; /* 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(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) add_effect(&effect, unwatch_htlc, htlc_unwatch_all(ctx, peer)); return next_state(ctx, effect, 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(ctx, effect, 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(ctx, effect, 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(ctx, peer); /* Now we need to wait for our commit to be done. */ add_effect(&effect, broadcast_tx, tx); add_effect(&effect, watch, bitcoin_watch(ctx, tx, BITCOIN_SPEND_OURS_DONE)); bits &= ~STATE_CLOSE_OURCOMMIT_BIT; bits |= STATE_CLOSE_SPENDOURS_BIT; return next_state(ctx, effect, 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(ctx, effect, 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(ctx, effect, BITS_TO_STATE(bits)); } else if (input_is(input, BITCOIN_HTLC_TOTHEM_SPENT)) { /* They revealed R value. */ add_effect(&effect, r_value, bitcoin_r_value(ctx, idata->htlc)); /* We don't care any more. */ add_effect(&effect, unwatch_htlc, htlc_unwatch(ctx, idata->htlc, INPUT_NO_MORE_HTLCS)); return effect; } else if (input_is(input, BITCOIN_HTLC_TOTHEM_TIMEOUT)){ tx = bitcoin_htlc_timeout(ctx, peer, idata->htlc); /* HTLC timed out, spend it back to us. */ add_effect(&effect, broadcast_tx, tx); /* Don't unwatch yet; they could yet * try to spend, revealing rvalue. */ /* We're done when that gets buried. */ add_effect(&effect, watch_htlc_spend, htlc_spend_watch(ctx, tx, idata->cmd, BITCOIN_HTLC_RETURN_SPEND_DONE)); return effect; } else if (input_is(input, INPUT_RVALUE)) { tx = bitcoin_htlc_spend(ctx, peer, idata->htlc); /* This gives us the r value. */ add_effect(&effect, r_value, r_value_from_cmd(ctx, peer, idata->htlc)); /* Spend it... */ add_effect(&effect, broadcast_tx, tx); /* We're done when it gets buried. */ add_effect(&effect, watch_htlc_spend, htlc_spend_watch(ctx, tx, idata->cmd, BITCOIN_HTLC_FULFILL_SPEND_DONE)); /* Don't care about this one any more. */ add_effect(&effect, unwatch_htlc, htlc_unwatch(ctx, idata->htlc, INPUT_NO_MORE_HTLCS)); return effect; } else if (input_is(input, BITCOIN_HTLC_FULFILL_SPEND_DONE)) { /* Stop watching spend, send * INPUT_NO_MORE_HTLCS when done. */ add_effect(&effect, unwatch_htlc_spend, htlc_spend_unwatch(ctx, idata->htlc, INPUT_NO_MORE_HTLCS)); return effect; } else if (input_is(input, BITCOIN_HTLC_RETURN_SPEND_DONE)) { /* Stop watching spend, send * INPUT_NO_MORE_HTLCS when done. */ add_effect(&effect, unwatch_htlc_spend, htlc_spend_unwatch(ctx, idata->htlc, INPUT_NO_MORE_HTLCS)); /* Don't need to watch the HTLC output any more, * either. */ add_effect(&effect, unwatch_htlc, htlc_unwatch(ctx, idata->htlc, INPUT_NO_MORE_HTLCS)); return effect; } else if (input_is(input, BITCOIN_HTLC_TOUS_TIMEOUT)) { /* They can spend, we no longer care * about this HTLC. */ add_effect(&effect, unwatch_htlc, htlc_unwatch(ctx, idata->htlc, INPUT_NO_MORE_HTLCS)); return effect; } } /* If we're just waiting for HTLCs, anything else is an error */ if (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(ctx, peer, idata->btc); add_effect(&effect, broadcast_tx, tx); add_effect(&effect, watch, bitcoin_watch(ctx, tx, BITCOIN_SPEND_THEIRS_DONE)); /* HTLC watches. */ htlcs = htlc_outputs_their_commit(ctx, peer, idata->btc, BITCOIN_HTLC_TOUS_TIMEOUT, BITCOIN_HTLC_TOTHEM_SPENT, BITCOIN_HTLC_TOTHEM_TIMEOUT); if (htlcs) { add_effect(&effect, watch_htlcs, htlcs); bits |= STATE_CLOSE_HTLCS_BIT; } bits |= STATE_CLOSE_SPENDTHEM_BIT; return next_state(ctx, effect, BITS_TO_STATE(bits)); /* This can happen multiple times: need to steal ALL */ } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { tx = bitcoin_steal(ctx, peer, idata->btc); if (!tx) return next_state(ctx, effect, STATE_ERR_INFORMATION_LEAK); add_effect(&effect, broadcast_tx, tx); add_effect(&effect, watch, bitcoin_watch(ctx, tx, BITCOIN_STEAL_DONE)); bits |= STATE_CLOSE_STEAL_BIT; return next_state(ctx, effect, BITS_TO_STATE(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(ctx, effect, STATE_ERR_INTERNAL); } /* State machine should handle all possible states. */ return next_state(ctx, effect, STATE_ERR_INTERNAL); unexpected_pkt: /* * We got a weird packet, so we need to close unilaterally. */ /* Don't reply to an error with an error. */ if (input_is(input, PKT_ERROR)) { add_effect(&effect, in_error, tal_steal(ctx, idata->pkt)); goto start_unilateral_close; } err = unexpected_pkt(ctx, input); goto err_start_unilateral_close; unexpected_pkt_nocleanup: /* * Unexpected packet, but nothing sent to chain yet, so no cleanup. */ err = unexpected_pkt(ctx, input); 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(ctx, effect, 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. */ add_effect(&effect, send_pkt, err); add_effect(&effect, stop_packets, true); add_effect(&effect, stop_commands, true); return next_state(ctx, effect, STATE_CLOSED); err_start_unilateral_close: /* * They timed out, or were broken; we are going to close unilaterally. */ add_effect(&effect, send_pkt, err); start_unilateral_close: /* * Close unilaterally. */ /* No more inputs, no more commands. */ add_effect(&effect, stop_packets, true); add_effect(&effect, stop_commands, true); tx = bitcoin_commit(ctx, peer); add_effect(&effect, broadcast_tx, tx); add_effect(&effect, watch, bitcoin_watch_delayed(ctx, tx, BITCOIN_ANCHOR_OURCOMMIT_DELAYPASSED)); /* HTLC watches. */ htlcs = htlc_outputs_our_commit(ctx, peer, tx, BITCOIN_HTLC_TOUS_TIMEOUT, BITCOIN_HTLC_TOTHEM_SPENT, BITCOIN_HTLC_TOTHEM_TIMEOUT); if (htlcs) { add_effect(&effect, watch_htlcs, htlcs); return next_state(ctx, effect, STATE_CLOSE_WAIT_OURCOMMIT_WITH_HTLCS); } return next_state(ctx, effect, STATE_CLOSE_WAIT_OURCOMMIT); err_start_unilateral_close_already_closing: /* * They timed out, or were broken; we are going to close unilaterally. */ add_effect(&effect, send_pkt, err); start_unilateral_close_already_closing: add_effect(&effect, cmd_close_done, false); /* * Close unilaterally. */ /* No more inputs, no more commands. */ add_effect(&effect, stop_packets, true); add_effect(&effect, stop_commands, true); tx = bitcoin_commit(ctx, peer); add_effect(&effect, broadcast_tx, tx); add_effect(&effect, watch, bitcoin_watch_delayed(ctx, tx, BITCOIN_ANCHOR_OURCOMMIT_DELAYPASSED)); /* We agreed to close: shouldn't have any HTLCs */ if (committed_to_htlcs(peer)) return next_state(ctx, effect, STATE_ERR_INTERNAL); return next_state(ctx, effect, STATE_CLOSE_WAIT_CLOSE_OURCOMMIT); them_unilateral: assert(input == BITCOIN_ANCHOR_THEIRSPEND); /* * Bitcoind tells us they did unilateral close. */ add_effect(&effect, send_pkt, pkt_err(ctx, "Commit tx noticed")); /* No more inputs, no more commands. */ add_effect(&effect, stop_packets, true); add_effect(&effect, stop_commands, true); tx = bitcoin_spend_theirs(ctx, peer, idata->btc); add_effect(&effect, broadcast_tx, tx); add_effect(&effect, watch, bitcoin_watch(ctx, 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. */ htlcs = htlc_outputs_their_commit(ctx, peer, idata->btc, BITCOIN_HTLC_TOUS_TIMEOUT, BITCOIN_HTLC_TOTHEM_SPENT, BITCOIN_HTLC_TOTHEM_TIMEOUT); if (htlcs) { add_effect(&effect, watch_htlcs, htlcs); return next_state(ctx, effect, STATE_CLOSE_WAIT_SPENDTHEM_WITH_HTLCS); } return next_state(ctx, effect, STATE_CLOSE_WAIT_SPENDTHEM); accept_htlc_update: err = accept_pkt_htlc_update(ctx, peer, idata->pkt, &decline, &htlcprog, &effect); if (err) goto err_start_unilateral_close; if (decline) { add_effect(&effect, send_pkt, decline); /* No update means no priority change. */ return next_state(ctx, effect, prio(state, STATE_NORMAL)); } add_effect(&effect, htlc_in_progress, htlcprog); add_effect(&effect, send_pkt, pkt_update_accept(ctx, peer)); return next_state(ctx, effect, prio(state, STATE_WAIT_FOR_UPDATE_SIG)); accept_htlc_routefail: err = accept_pkt_htlc_routefail(ctx, peer, idata->pkt, &htlcprog, &effect); if (err) goto err_start_unilateral_close; add_effect(&effect, htlc_in_progress, htlcprog); add_effect(&effect, send_pkt, pkt_update_accept(ctx, peer)); return next_state(ctx, effect, prio(state, STATE_WAIT_FOR_UPDATE_SIG)); accept_htlc_timedout: err = accept_pkt_htlc_timedout(ctx, peer, idata->pkt, &htlcprog, &effect); if (err) goto err_start_unilateral_close; add_effect(&effect, htlc_in_progress, htlcprog); add_effect(&effect, send_pkt, pkt_update_accept(ctx, peer)); return next_state(ctx, effect, prio(state, STATE_WAIT_FOR_UPDATE_SIG)); accept_htlc_fulfill: err = accept_pkt_htlc_fulfill(ctx, peer, idata->pkt, &htlcprog, &effect); if (err) goto err_start_unilateral_close; add_effect(&effect, htlc_in_progress, htlcprog); add_effect(&effect, send_pkt, pkt_update_accept(ctx, peer)); add_effect(&effect, r_value, r_value_from_pkt(ctx, idata->pkt)); return next_state(ctx, effect, prio(state, STATE_WAIT_FOR_UPDATE_SIG)); start_closing: /* * Start a mutual close. */ /* Protocol doesn't (currently?) allow closing with HTLCs. */ if (committed_to_htlcs(peer)) { add_effect(&effect, cmd_close_done, false); err = pkt_err(ctx, "Close forced due to HTLCs"); goto err_start_unilateral_close; } add_effect(&effect, close_timeout, INPUT_CLOSE_COMPLETE_TIMEOUT); add_effect(&effect, watch, bitcoin_watch_close(ctx, peer, BITCOIN_CLOSE_DONE)); /* As soon as we send packet, they could close. */ add_effect(&effect, send_pkt, pkt_close(ctx, peer)); return next_state(ctx, effect, STATE_WAIT_FOR_CLOSE_COMPLETE); accept_closing: err = accept_pkt_close(ctx, peer, idata->pkt, &effect); if (err) goto err_start_unilateral_close; /* As soon as we send packet, they could close. */ add_effect(&effect, watch, bitcoin_watch_close(ctx, peer, BITCOIN_CLOSE_DONE)); add_effect(&effect, send_pkt, pkt_close_complete(ctx, peer)); /* No more commands, we're already closing. */ add_effect(&effect, stop_commands, true); return next_state(ctx, effect, STATE_WAIT_FOR_CLOSE_ACK); instant_close: /* * Closing, but we haven't sent anything to the blockchain so * there's nothing to clean up. */ add_effect(&effect, cmd_close_done, true); /* FIXME: Should we tell other side we're going? */ add_effect(&effect, stop_packets, true); add_effect(&effect, stop_commands, true); /* We can't have any HTLCs, since we haven't started. */ if (committed_to_htlcs(peer)) return next_state(ctx, effect, STATE_ERR_INTERNAL); return next_state(ctx, effect, STATE_CLOSED); fail_during_close: /* * We've broadcast close tx; if anything goes wrong, we just close * connection and wait. */ add_effect(&effect, stop_packets, true); /* Once close tx is deep enough, we consider it done. */ if (input_is(input, BITCOIN_CLOSE_DONE)) { return next_state(ctx, effect, STATE_CLOSED); } else if (input_is(input, BITCOIN_ANCHOR_THEIRSPEND)) { /* A reorganization could make this happen. */ tx = bitcoin_spend_theirs(ctx, peer, idata->btc); add_effect(&effect, broadcast_tx, tx); add_effect(&effect, watch, bitcoin_watch(ctx, tx, BITCOIN_SPEND_THEIRS_DONE)); htlcs = htlc_outputs_their_commit(ctx, peer, idata->btc, BITCOIN_HTLC_TOUS_TIMEOUT, BITCOIN_HTLC_TOTHEM_SPENT, BITCOIN_HTLC_TOTHEM_TIMEOUT); /* Expect either close or spendthem to complete */ if (htlcs) { /* FIXME: Make sure caller uses INPUT_RVAL * if they were in the middle of FULFILL! */ add_effect(&effect, watch_htlcs, htlcs); return next_state(ctx, effect, STATE_CLOSE_WAIT_SPENDTHEM_CLOSE_WITH_HTLCS); } return next_state(ctx, effect, STATE_CLOSE_WAIT_SPENDTHEM_CLOSE); } else if (input_is(input, BITCOIN_ANCHOR_OTHERSPEND)) { tx = bitcoin_steal(ctx, peer, idata->btc); if (!tx) return next_state(ctx, effect, STATE_ERR_INFORMATION_LEAK); add_effect(&effect, broadcast_tx, tx); add_effect(&effect, watch, bitcoin_watch(ctx, tx, BITCOIN_STEAL_DONE)); /* Expect either close or steal to complete */ return next_state(ctx, effect, STATE_CLOSE_WAIT_STEAL_CLOSE); } else if (input_is(input, BITCOIN_ANCHOR_UNSPENT)) { return next_state(ctx, effect, STATE_ERR_ANCHOR_LOST); } return next_state(ctx, effect, STATE_ERR_INTERNAL); old_commit_spotted: /* * bitcoind reported a broadcast of the not-latest commit tx. */ add_effect(&effect, send_pkt, pkt_err(ctx, "Otherspend noticed")); /* No more packets, no more commands. */ add_effect(&effect, stop_packets, true); add_effect(&effect, stop_commands, true); /* If we can't find it, we're lost. */ tx = bitcoin_steal(ctx, peer, idata->btc); if (!tx) return next_state(ctx, effect, STATE_ERR_INFORMATION_LEAK); add_effect(&effect, broadcast_tx, tx); add_effect(&effect, watch, bitcoin_watch(ctx, tx, BITCOIN_STEAL_DONE)); return next_state(ctx, effect, STATE_CLOSE_WAIT_STEAL); }