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94e42f2384
core-lightning/openingd/openingd.c
Simon Vrouwe 94e42f2384 openingd: prioritize incoming peer traffic over handling (and sending out) gossip 
- reduces probability for a deadlock where we block on sending data because
  the other peer cannot receive because it blocks on sending data etc.
- when either side sends so much data that it fills up the kernel/network buffer
- however sending out gossip can still block when (malicious) peer never receives
2018-09-20 03:28:42 +00:00

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#include <bitcoin/block.h>
#include <bitcoin/chainparams.h>
#include <bitcoin/privkey.h>
#include <bitcoin/script.h>
#include <ccan/array_size/array_size.h>
#include <ccan/breakpoint/breakpoint.h>
#include <ccan/cast/cast.h>
#include <ccan/fdpass/fdpass.h>
#include <ccan/tal/str/str.h>
#include <common/crypto_sync.h>
#include <common/derive_basepoints.h>
#include <common/funding_tx.h>
#include <common/gen_peer_status_wire.h>
#include <common/initial_channel.h>
#include <common/key_derive.h>
#include <common/peer_billboard.h>
#include <common/peer_failed.h>
#include <common/pseudorand.h>
#include <common/read_peer_msg.h>
#include <common/status.h>
#include <common/subdaemon.h>
#include <common/type_to_string.h>
#include <common/version.h>
#include <common/wire_error.h>
#include <errno.h>
#include <hsmd/gen_hsm_client_wire.h>
#include <inttypes.h>
#include <openingd/gen_opening_wire.h>
#include <poll.h>
#include <secp256k1.h>
#include <stdio.h>
#include <wally_bip32.h>
#include <wire/gen_peer_wire.h>
#include <wire/peer_wire.h>
#include <wire/wire.h>
#include <wire/wire_sync.h>
/* stdin == requests, 3 == peer, 4 == gossip */
#define REQ_FD STDIN_FILENO
#define PEER_FD 3
#define GOSSIP_FD 4
#define HSM_FD 5
struct state {
struct crypto_state cs;
struct pubkey next_per_commit[NUM_SIDES];
/* Constriants on a channel they open. */
u32 minimum_depth;
u32 min_feerate, max_feerate;
struct basepoints our_points;
struct pubkey our_funding_pubkey;
/* Initially temporary, then final channel id. */
struct channel_id channel_id;
/* Funding and feerate: set by opening peer. */
u64 funding_satoshis, push_msat;
u32 feerate_per_kw;
struct bitcoin_txid funding_txid;
u16 funding_txout;
struct channel_config localconf, remoteconf;
/* Limits on what remote config we accept */
u32 max_to_self_delay;
u64 min_effective_htlc_capacity_msat;
struct channel *channel;
bool can_accept_channel;
const struct chainparams *chainparams;
};
static void negotiation_aborted(struct state *state, bool am_funder,
const char *why)
{
status_debug("aborted opening negotiaion: %s", why);
peer_billboard(true, why);
/* If necessary, tell master that funding failed. */
if (am_funder) {
u8 *msg = towire_opening_funder_failed(NULL, why);
wire_sync_write(REQ_FD, take(msg));
}
/* Reset state. */
memset(&state->channel_id, 0, sizeof(state->channel_id));
state->channel = tal_free(state->channel);
}
/* For negotiation failures: we tell them it's their fault. */
static void negotiation_failed(struct state *state, bool am_funder,
const char *fmt, ...)
{
va_list ap;
const char *errmsg;
u8 *msg;
va_start(ap, fmt);
errmsg = tal_vfmt(tmpctx, fmt, ap);
va_end(ap);
msg = towire_errorfmt(NULL, &state->channel_id,
"You gave bad parameters: %s", errmsg);
sync_crypto_write(&state->cs, PEER_FD, take(msg));
negotiation_aborted(state, am_funder, errmsg);
}
static bool check_config_bounds(struct state *state,
const struct channel_config *remoteconf,
bool am_funder)
{
u64 capacity_msat;
u64 reserve_msat;
/* BOLT #2:
*
* The receiving node MUST fail the channel if:
*...
* - `to_self_delay` is unreasonably large.
*/
if (remoteconf->to_self_delay > state->max_to_self_delay) {
negotiation_failed(state, am_funder,
"to_self_delay %u larger than %u",
remoteconf->to_self_delay,
state->max_to_self_delay);
return false;
}
/* BOLT #2:
*
* The receiving node MAY fail the channel if:
*...
* - `funding_satoshis` is too small.
* - it considers `htlc_minimum_msat` too large.
* - it considers `max_htlc_value_in_flight_msat` too small.
* - it considers `channel_reserve_satoshis` too large.
* - it considers `max_accepted_htlcs` too small.
*/
/* We accumulate this into an effective bandwidth minimum. */
/* Overflow check before capacity calc. */
if (remoteconf->channel_reserve_satoshis > state->funding_satoshis) {
negotiation_failed(state, am_funder,
"channel_reserve_satoshis %"PRIu64
" too large for funding_satoshis %"PRIu64,
remoteconf->channel_reserve_satoshis,
state->funding_satoshis);
return false;
}
/* Consider highest reserve. */
reserve_msat = remoteconf->channel_reserve_satoshis * 1000;
if (state->localconf.channel_reserve_satoshis * 1000 > reserve_msat)
reserve_msat = state->localconf.channel_reserve_satoshis * 1000;
capacity_msat = state->funding_satoshis * 1000 - reserve_msat;
if (remoteconf->max_htlc_value_in_flight_msat < capacity_msat)
capacity_msat = remoteconf->max_htlc_value_in_flight_msat;
if (remoteconf->htlc_minimum_msat * (u64)1000 > capacity_msat) {
negotiation_failed(state, am_funder,
"htlc_minimum_msat %"PRIu64
" too large for funding_satoshis %"PRIu64
" capacity_msat %"PRIu64,
remoteconf->htlc_minimum_msat,
state->funding_satoshis,
capacity_msat);
return false;
}
if (capacity_msat < state->min_effective_htlc_capacity_msat) {
negotiation_failed(state, am_funder,
"channel capacity with funding %"PRIu64" msat,"
" reserves %"PRIu64"/%"PRIu64" msat,"
" max_htlc_value_in_flight_msat %"PRIu64
" is %"PRIu64" msat, which is below %"PRIu64" msat",
state->funding_satoshis * 1000,
remoteconf->channel_reserve_satoshis * 1000,
state->localconf.channel_reserve_satoshis * 1000,
remoteconf->max_htlc_value_in_flight_msat,
capacity_msat,
state->min_effective_htlc_capacity_msat);
return false;
}
/* We don't worry about how many HTLCs they accept, as long as > 0! */
if (remoteconf->max_accepted_htlcs == 0) {
negotiation_failed(state, am_funder,
"max_accepted_htlcs %u invalid",
remoteconf->max_accepted_htlcs);
return false;
}
/* BOLT #2:
*
* The receiving node MUST fail the channel if:
*...
* - `max_accepted_htlcs` is greater than 483.
*/
if (remoteconf->max_accepted_htlcs > 483) {
negotiation_failed(state, am_funder,
"max_accepted_htlcs %u too large",
remoteconf->max_accepted_htlcs);
return false;
}
/* BOLT #2:
*
* The receiving node MUST fail the channel if:
*...
* - `dust_limit_satoshis` is greater than `channel_reserve_satoshis`.
*/
if (remoteconf->dust_limit_satoshis
> remoteconf->channel_reserve_satoshis) {
negotiation_failed(state, am_funder,
"dust_limit_satoshis %"PRIu64
" too large for channel_reserve_satoshis %"
PRIu64,
remoteconf->dust_limit_satoshis,
remoteconf->channel_reserve_satoshis);
return false;
}
return true;
}
/* We always set channel_reserve_satoshis to 1%, rounded up. */
static void set_reserve(struct state *state)
{
state->localconf.channel_reserve_satoshis
= (state->funding_satoshis + 99) / 100;
/* BOLT #2:
*
* The sending node:
*...
* - MUST set `channel_reserve_satoshis` greater than or equal to
* `dust_limit_satoshis`.
*/
if (state->localconf.channel_reserve_satoshis
< state->localconf.dust_limit_satoshis)
state->localconf.channel_reserve_satoshis
= state->localconf.dust_limit_satoshis;
}
/* BOLT #2:
*
* The sending node:
*...
* - MUST ensure `temporary_channel_id` is unique from any other channel ID
* with the same peer.
*/
static void temporary_channel_id(struct channel_id *channel_id)
{
size_t i;
for (i = 0; i < sizeof(*channel_id); i++)
channel_id->id[i] = pseudorand(256);
}
/* Handle random messages we might get during opening negotiation,
* returning the first non-handled one, or NULL if we aborted negotiation. */
static u8 *opening_negotiate_msg(const tal_t *ctx, struct state *state,
bool am_funder)
{
for (;;) {
u8 *msg;
bool from_gossipd;
char *err;
bool all_channels;
struct channel_id actual;
clean_tmpctx();
msg = peer_or_gossip_sync_read(ctx, PEER_FD, GOSSIP_FD,
&state->cs, &from_gossipd);
if (from_gossipd) {
handle_gossip_msg(PEER_FD, &state->cs, take(msg));
continue;
}
if (is_msg_for_gossipd(msg)) {
wire_sync_write(GOSSIP_FD, take(msg));
continue;
}
if (is_peer_error(tmpctx, msg, &state->channel_id,
&err, &all_channels)) {
/* BOLT #1:
*
* - if no existing channel is referred to by the
* message:
* - MUST ignore the message.
*/
if (!err) {
tal_free(msg);
continue;
}
if (am_funder) {
msg = towire_opening_funder_failed(NULL, err);
wire_sync_write(REQ_FD, take(msg));
}
/* Close connection on all_channels error. */
if (all_channels)
peer_failed_received_errmsg(PEER_FD, GOSSIP_FD,
&state->cs, err,
NULL);
negotiation_aborted(state, am_funder,
tal_fmt(tmpctx, "They sent error %s",
err));
/* Return NULL so caller knows to stop negotiating. */
return NULL;
}
if (is_wrong_channel(msg, &state->channel_id, &actual)) {
status_trace("Rejecting %s for unknown channel_id %s",
wire_type_name(fromwire_peektype(msg)),
type_to_string(tmpctx, struct channel_id,
&actual));
sync_crypto_write(&state->cs, PEER_FD,
take(towire_errorfmt(NULL, &actual,
"Multiple channels"
" unsupported")));
tal_free(msg);
continue;
}
return msg;
}
}
static u8 *funder_channel(struct state *state,
u64 change_satoshis, u32 change_keyindex,
u8 channel_flags,
struct utxo **utxos,
const struct ext_key *bip32_base)
{
struct channel_id id_in;
u8 *msg;
struct bitcoin_tx *tx;
struct basepoints theirs;
struct pubkey their_funding_pubkey;
struct pubkey *changekey;
secp256k1_ecdsa_signature sig;
u32 minimum_depth;
const u8 *wscript;
struct bitcoin_tx *funding;
set_reserve(state);
temporary_channel_id(&state->channel_id);
if (state->funding_satoshis > state->chainparams->max_funding_satoshi)
status_failed(STATUS_FAIL_MASTER_IO,
"funding_satoshis must be < %"PRIu64", not %"PRIu64,
state->chainparams->max_funding_satoshi,
state->funding_satoshis);
/* BOLT #2:
*
* The sending node:
*...
* - MUST set `push_msat` to equal or less than 1000 *
* `funding_satoshis`.
*/
if (state->push_msat > 1000 * state->funding_satoshis)
status_failed(STATUS_FAIL_MASTER_IO,
"push-msat must be < %"PRIu64,
1000 * state->funding_satoshis);
msg = towire_open_channel(state,
&state->chainparams->genesis_blockhash,
&state->channel_id,
state->funding_satoshis, state->push_msat,
state->localconf.dust_limit_satoshis,
state->localconf.max_htlc_value_in_flight_msat,
state->localconf.channel_reserve_satoshis,
state->localconf.htlc_minimum_msat,
state->feerate_per_kw,
state->localconf.to_self_delay,
state->localconf.max_accepted_htlcs,
&state->our_funding_pubkey,
&state->our_points.revocation,
&state->our_points.payment,
&state->our_points.delayed_payment,
&state->our_points.htlc,
&state->next_per_commit[LOCAL],
channel_flags);
sync_crypto_write(&state->cs, PEER_FD, msg);
peer_billboard(false,
"Funding channel: offered, now waiting for accept_channel");
msg = opening_negotiate_msg(tmpctx, state, true);
if (!msg)
return NULL;
/* BOLT #2:
*
* The receiving node MUST fail the channel if:
*...
* - `funding_pubkey`, `revocation_basepoint`, `htlc_basepoint`,
* `payment_basepoint`, or `delayed_payment_basepoint` are not
* valid DER-encoded compressed secp256k1 pubkeys.
*/
if (!fromwire_accept_channel(msg, &id_in,
&state->remoteconf.dust_limit_satoshis,
&state->remoteconf
.max_htlc_value_in_flight_msat,
&state->remoteconf
.channel_reserve_satoshis,
&state->remoteconf.htlc_minimum_msat,
&minimum_depth,
&state->remoteconf.to_self_delay,
&state->remoteconf.max_accepted_htlcs,
&their_funding_pubkey,
&theirs.revocation,
&theirs.payment,
&theirs.delayed_payment,
&theirs.htlc,
&state->next_per_commit[REMOTE]))
peer_failed(&state->cs,
&state->channel_id,
"Parsing accept_channel %s", tal_hex(msg, msg));
/* BOLT #2:
*
* The `temporary_channel_id` MUST be the same as the
* `temporary_channel_id` in the `open_channel` message. */
if (!channel_id_eq(&id_in, &state->channel_id))
peer_failed(&state->cs,
&state->channel_id,
"accept_channel ids don't match: sent %s got %s",
type_to_string(msg, struct channel_id, &id_in),
type_to_string(msg, struct channel_id,
&state->channel_id));
/* BOLT #2:
*
* The receiver:
*...
* - if `minimum_depth` is unreasonably large:
* - MAY reject the channel.
*/
if (minimum_depth > 10) {
negotiation_failed(state, true,
"minimum_depth %u larger than %u",
minimum_depth, 10);
return NULL;
}
/* BOLT #2:
*
* The receiver:
*...
* - if `channel_reserve_satoshis` is less than `dust_limit_satoshis`
* within the `open_channel` message:
* - MUST reject the channel.
*
* - if `channel_reserve_satoshis` from the `open_channel` message is
* less than `dust_limit_satoshis`:
* - MUST reject the channel.
*/
if (state->remoteconf.channel_reserve_satoshis
< state->localconf.dust_limit_satoshis) {
negotiation_failed(state, true,
"channel reserve %"PRIu64
" would be below our dust %"PRIu64,
state->remoteconf.channel_reserve_satoshis,
state->localconf.dust_limit_satoshis);
return NULL;
}
if (state->localconf.channel_reserve_satoshis
< state->remoteconf.dust_limit_satoshis) {
negotiation_failed(state, true,
"dust limit %"PRIu64
" would be above our reserve %"PRIu64,
state->remoteconf.dust_limit_satoshis,
state->localconf.channel_reserve_satoshis);
return NULL;
}
if (!check_config_bounds(state, &state->remoteconf, true))
return NULL;
/* Now, ask create funding transaction to pay those two addresses. */
if (change_satoshis) {
changekey = tal(tmpctx, struct pubkey);
if (!bip32_pubkey(bip32_base, changekey, change_keyindex))
status_failed(STATUS_FAIL_MASTER_IO,
"Bad change key %u", change_keyindex);
} else
changekey = NULL;
funding = funding_tx(state, &state->funding_txout,
cast_const2(const struct utxo **, utxos),
state->funding_satoshis,
&state->our_funding_pubkey,
&their_funding_pubkey,
change_satoshis, changekey,
bip32_base);
bitcoin_txid(funding, &state->funding_txid);
state->channel = new_initial_channel(state,
&state->chainparams->genesis_blockhash,
&state->funding_txid,
state->funding_txout,
state->funding_satoshis,
state->funding_satoshis * 1000
- state->push_msat,
state->feerate_per_kw,
&state->localconf,
&state->remoteconf,
&state->our_points, &theirs,
&state->our_funding_pubkey,
&their_funding_pubkey,
LOCAL);
if (!state->channel)
peer_failed(&state->cs,
&state->channel_id,
"could not create channel with given config");
/* BOLT #2:
*
* ### The `funding_created` Message
*
* This message describes the outpoint which the funder has created
* for the initial commitment transactions. After receiving the
* peer's signature, via `funding_signed`, it will broadcast the funding
* transaction.
*/
tx = initial_channel_tx(state, &wscript, state->channel,
&state->next_per_commit[REMOTE], REMOTE);
if (!tx) {
negotiation_failed(state, true,
"Could not meet their fees and reserve");
return NULL;
}
msg = towire_hsm_sign_remote_commitment_tx(NULL,
tx,
&state->channel->funding_pubkey[REMOTE],
state->channel->funding_msat / 1000);
wire_sync_write(HSM_FD, take(msg));
msg = wire_sync_read(tmpctx, HSM_FD);
if (!fromwire_hsm_sign_tx_reply(msg, &sig))
status_failed(STATUS_FAIL_HSM_IO, "Bad sign_tx_reply %s",
tal_hex(tmpctx, msg));
status_trace("signature %s on tx %s using key %s",
type_to_string(tmpctx, secp256k1_ecdsa_signature, &sig),
type_to_string(tmpctx, struct bitcoin_tx, tx),
type_to_string(tmpctx, struct pubkey,
&state->our_funding_pubkey));
msg = towire_funding_created(state, &state->channel_id,
&state->funding_txid,
state->funding_txout,
&sig);
sync_crypto_write(&state->cs, PEER_FD, msg);
/* BOLT #2:
*
* ### The `funding_signed` Message
*
* This message gives the funder the signature it needs for the first
* commitment transaction, so it can broadcast the transaction knowing
* that funds can be redeemed, if need be.
*/
peer_billboard(false,
"Funding channel: create first tx, now waiting for their signature");
msg = opening_negotiate_msg(tmpctx, state, true);
if (!msg)
return NULL;
if (!fromwire_funding_signed(msg, &id_in, &sig))
peer_failed(&state->cs,
&state->channel_id,
"Parsing funding_signed: %s", tal_hex(msg, msg));
/* BOLT #2:
*
* This message introduces the `channel_id` to identify the channel.
* It's derived from the funding transaction by combining the
* `funding_txid` and the `funding_output_index`, using big-endian
* exclusive-OR (i.e. `funding_output_index` alters the last 2
* bytes).
*/
derive_channel_id(&state->channel_id,
&state->funding_txid, state->funding_txout);
if (!channel_id_eq(&id_in, &state->channel_id))
peer_failed(&state->cs, &id_in,
"funding_signed ids don't match: expected %s got %s",
type_to_string(msg, struct channel_id,
&state->channel_id),
type_to_string(msg, struct channel_id, &id_in));
/* BOLT #2:
*
* The recipient:
* - if `signature` is incorrect:
* - MUST fail the channel.
*/
tx = initial_channel_tx(state, &wscript, state->channel,
&state->next_per_commit[LOCAL], LOCAL);
if (!tx) {
negotiation_failed(state, true,
"Could not meet our fees and reserve");
return NULL;
}
if (!check_tx_sig(tx, 0, NULL, wscript, &their_funding_pubkey, &sig)) {
peer_failed(&state->cs,
&state->channel_id,
"Bad signature %s on tx %s using key %s",
type_to_string(tmpctx, secp256k1_ecdsa_signature,
&sig),
type_to_string(tmpctx, struct bitcoin_tx, tx),
type_to_string(tmpctx, struct pubkey,
&their_funding_pubkey));
}
peer_billboard(false, "Funding channel: opening negotiation succeeded");
/* BOLT #2:
*
* The recipient:
*...
* - on receipt of a valid `funding_signed`:
* - SHOULD broadcast the funding transaction.
*/
return towire_opening_funder_reply(state,
&state->remoteconf,
tx,
&sig,
&state->cs,
&theirs.revocation,
&theirs.payment,
&theirs.htlc,
&theirs.delayed_payment,
&state->next_per_commit[REMOTE],
minimum_depth,
&their_funding_pubkey,
&state->funding_txid,
state->feerate_per_kw,
state->localconf.channel_reserve_satoshis);
}
static u8 *fundee_channel(struct state *state, const u8 *open_channel_msg)
{
struct channel_id id_in;
struct basepoints theirs;
struct pubkey their_funding_pubkey;
secp256k1_ecdsa_signature theirsig, sig;
struct bitcoin_tx *local_commit, *remote_commit;
struct bitcoin_blkid chain_hash;
u8 *msg;
const u8 *wscript;
u8 channel_flags;
/* BOLT #2:
*
* The receiving node MUST fail the channel if:
*...
* - `funding_pubkey`, `revocation_basepoint`, `htlc_basepoint`,
* `payment_basepoint`, or `delayed_payment_basepoint` are not valid
* DER-encoded compressed secp256k1 pubkeys.
*/
if (!fromwire_open_channel(open_channel_msg, &chain_hash,
&state->channel_id,
&state->funding_satoshis, &state->push_msat,
&state->remoteconf.dust_limit_satoshis,
&state->remoteconf.max_htlc_value_in_flight_msat,
&state->remoteconf.channel_reserve_satoshis,
&state->remoteconf.htlc_minimum_msat,
&state->feerate_per_kw,
&state->remoteconf.to_self_delay,
&state->remoteconf.max_accepted_htlcs,
&their_funding_pubkey,
&theirs.revocation,
&theirs.payment,
&theirs.delayed_payment,
&theirs.htlc,
&state->next_per_commit[REMOTE],
&channel_flags))
peer_failed(&state->cs, NULL,
"Bad open_channel %s",
tal_hex(open_channel_msg, open_channel_msg));
/* We can't handle talking about more than one channel at once. */
if (!state->can_accept_channel) {
u8 *errmsg;
errmsg = towire_errorfmt(NULL, &state->channel_id,
"Already have active channel");
sync_crypto_write(&state->cs, PEER_FD, take(errmsg));
return NULL;
}
/* BOLT #2:
*
* The receiver:
* - if the `chain_hash` value, within the `open_channel`, message is
* set to a hash of a chain that is unknown to the receiver:
* - MUST reject the channel.
*/
if (!bitcoin_blkid_eq(&chain_hash,
&state->chainparams->genesis_blockhash)) {
negotiation_failed(state, false,
"Unknown chain-hash %s",
type_to_string(tmpctx,
struct bitcoin_blkid,
&chain_hash));
return NULL;
}
/* BOLT #2 FIXME:
*
* The receiving node ... MUST fail the channel if `funding-satoshis`
* is greater than or equal to 2^24 */
if (state->funding_satoshis > state->chainparams->max_funding_satoshi) {
negotiation_failed(state, false,
"funding_satoshis %"PRIu64" too large",
state->funding_satoshis);
return NULL;
}
/* BOLT #2:
*
* The receiving node MUST fail the channel if:
* - `push_msat` is greater than `funding_satoshis` * 1000.
*/
if (state->push_msat > state->funding_satoshis * 1000) {
peer_failed(&state->cs,
&state->channel_id,
"Our push_msat %"PRIu64
" would be too large for funding_satoshis %"PRIu64,
state->push_msat, state->funding_satoshis);
return NULL;
}
/* BOLT #2:
*
* The receiving node MUST fail the channel if:
*...
* - it considers `feerate_per_kw` too small for timely processing or
* unreasonably large.
*/
if (state->feerate_per_kw < state->min_feerate) {
negotiation_failed(state, false,
"feerate_per_kw %u below minimum %u",
state->feerate_per_kw, state->min_feerate);
return NULL;
}
if (state->feerate_per_kw > state->max_feerate) {
negotiation_failed(state, false,
"feerate_per_kw %u above maximum %u",
state->feerate_per_kw, state->max_feerate);
return NULL;
}
set_reserve(state);
/* BOLT #2:
*
* The sender:
*...
* - MUST set `channel_reserve_satoshis` greater than or equal to
* `dust_limit_satoshis` from the `open_channel` message.
* - MUST set `dust_limit_satoshis` less than or equal to
* `channel_reserve_satoshis` from the `open_channel` message.
*/
if (state->localconf.channel_reserve_satoshis
< state->remoteconf.dust_limit_satoshis) {
negotiation_failed(state, false,
"Our channel reserve %"PRIu64
" would be below their dust %"PRIu64,
state->localconf.channel_reserve_satoshis,
state->remoteconf.dust_limit_satoshis);
return NULL;
}
if (state->localconf.dust_limit_satoshis
> state->remoteconf.channel_reserve_satoshis) {
negotiation_failed(state, false,
"Our dust limit %"PRIu64
" would be above their reserve %"PRIu64,
state->localconf.dust_limit_satoshis,
state->remoteconf.channel_reserve_satoshis);
return NULL;
}
if (!check_config_bounds(state, &state->remoteconf, false))
return NULL;
msg = towire_accept_channel(state, &state->channel_id,
state->localconf.dust_limit_satoshis,
state->localconf
.max_htlc_value_in_flight_msat,
state->localconf.channel_reserve_satoshis,
state->localconf.htlc_minimum_msat,
state->minimum_depth,
state->localconf.to_self_delay,
state->localconf.max_accepted_htlcs,
&state->our_funding_pubkey,
&state->our_points.revocation,
&state->our_points.payment,
&state->our_points.delayed_payment,
&state->our_points.htlc,
&state->next_per_commit[LOCAL]);
sync_crypto_write(&state->cs, PEER_FD, take(msg));
peer_billboard(false,
"Incoming channel: accepted, now waiting for them to create funding tx");
msg = opening_negotiate_msg(tmpctx, state, false);
if (!msg)
return NULL;
if (!fromwire_funding_created(msg, &id_in,
&state->funding_txid,
&state->funding_txout,
&theirsig))
peer_failed(&state->cs,
&state->channel_id,
"Parsing funding_created");
/* BOLT #2:
*
* The `temporary_channel_id` MUST be the same as the
* `temporary_channel_id` in the `open_channel` message.
*/
if (!channel_id_eq(&id_in, &state->channel_id))
peer_failed(&state->cs, &id_in,
"funding_created ids don't match: sent %s got %s",
type_to_string(msg, struct channel_id,
&state->channel_id),
type_to_string(msg, struct channel_id, &id_in));
state->channel = new_initial_channel(state,
&chain_hash,
&state->funding_txid,
state->funding_txout,
state->funding_satoshis,
state->push_msat,
state->feerate_per_kw,
&state->localconf,
&state->remoteconf,
&state->our_points, &theirs,
&state->our_funding_pubkey,
&their_funding_pubkey,
REMOTE);
if (!state->channel)
peer_failed(&state->cs,
&state->channel_id,
"We could not create channel with given config");
/* BOLT #2:
*
* The recipient:
* - if `signature` is incorrect:
* - MUST fail the channel.
*/
local_commit = initial_channel_tx(state, &wscript, state->channel,
&state->next_per_commit[LOCAL], LOCAL);
if (!local_commit) {
negotiation_failed(state, false,
"Could not meet our fees and reserve");
return NULL;
}
if (!check_tx_sig(local_commit, 0, NULL, wscript, &their_funding_pubkey,
&theirsig)) {
peer_failed(&state->cs,
&state->channel_id,
"Bad signature %s on tx %s using key %s",
type_to_string(tmpctx, secp256k1_ecdsa_signature,
&theirsig),
type_to_string(tmpctx, struct bitcoin_tx, local_commit),
type_to_string(tmpctx, struct pubkey,
&their_funding_pubkey));
}
/* BOLT #2:
*
* This message introduces the `channel_id` to identify the
* channel. It's derived from the funding transaction by combining the
* `funding_txid` and the `funding_output_index`, using big-endian
* exclusive-OR (i.e. `funding_output_index` alters the last 2 bytes).
*/
derive_channel_id(&state->channel_id,
&state->funding_txid, state->funding_txout);
/* BOLT #2:
*
* ### The `funding_signed` Message
*
* This message gives the funder the signature it needs for the first
* commitment transaction, so it can broadcast the transaction knowing
* that funds can be redeemed, if need be.
*/
remote_commit = initial_channel_tx(state, &wscript, state->channel,
&state->next_per_commit[REMOTE],
REMOTE);
if (!remote_commit) {
negotiation_failed(state, false,
"Could not meet their fees and reserve");
return NULL;
}
/* FIXME: Perhaps we should have channeld generate this, so we
* can't possibly send before channel committed? */
msg = towire_hsm_sign_remote_commitment_tx(NULL,
remote_commit,
&state->channel->funding_pubkey[REMOTE],
state->channel->funding_msat / 1000);
wire_sync_write(HSM_FD, take(msg));
msg = wire_sync_read(tmpctx, HSM_FD);
if (!fromwire_hsm_sign_tx_reply(msg, &sig))
status_failed(STATUS_FAIL_HSM_IO,
"Bad sign_tx_reply %s", tal_hex(tmpctx, msg));
/* We don't send this ourselves: channeld does, because master needs
* to save state to disk before doing so. */
msg = towire_funding_signed(state, &state->channel_id, &sig);
return towire_opening_fundee(state,
&state->remoteconf,
local_commit,
&theirsig,
&state->cs,
&theirs.revocation,
&theirs.payment,
&theirs.htlc,
&theirs.delayed_payment,
&state->next_per_commit[REMOTE],
&their_funding_pubkey,
&state->funding_txid,
state->funding_txout,
state->funding_satoshis,
state->push_msat,
channel_flags,
state->feerate_per_kw,
msg,
state->localconf.channel_reserve_satoshis);
}
static u8 *handle_peer_in(struct state *state)
{
u8 *msg = sync_crypto_read(tmpctx, &state->cs, PEER_FD);
enum wire_type t = fromwire_peektype(msg);
struct channel_id channel_id;
switch (t) {
case WIRE_OPEN_CHANNEL:
return fundee_channel(state, msg);
/* These are handled by handle_peer_gossip_or_error. */
case WIRE_PING:
case WIRE_PONG:
case WIRE_CHANNEL_ANNOUNCEMENT:
case WIRE_NODE_ANNOUNCEMENT:
case WIRE_CHANNEL_UPDATE:
case WIRE_QUERY_SHORT_CHANNEL_IDS:
case WIRE_REPLY_SHORT_CHANNEL_IDS_END:
case WIRE_QUERY_CHANNEL_RANGE:
case WIRE_REPLY_CHANNEL_RANGE:
case WIRE_GOSSIP_TIMESTAMP_FILTER:
case WIRE_ERROR:
case WIRE_CHANNEL_REESTABLISH:
/* These are all protocol violations at this stage. */
case WIRE_INIT:
case WIRE_ACCEPT_CHANNEL:
case WIRE_FUNDING_CREATED:
case WIRE_FUNDING_SIGNED:
case WIRE_FUNDING_LOCKED:
case WIRE_SHUTDOWN:
case WIRE_CLOSING_SIGNED:
case WIRE_UPDATE_ADD_HTLC:
case WIRE_UPDATE_FULFILL_HTLC:
case WIRE_UPDATE_FAIL_HTLC:
case WIRE_UPDATE_FAIL_MALFORMED_HTLC:
case WIRE_COMMITMENT_SIGNED:
case WIRE_REVOKE_AND_ACK:
case WIRE_UPDATE_FEE:
case WIRE_ANNOUNCEMENT_SIGNATURES:
/* Standard cases */
if (handle_peer_gossip_or_error(PEER_FD, GOSSIP_FD, &state->cs,
&state->channel_id, msg))
return NULL;
break;
}
sync_crypto_write(&state->cs, PEER_FD,
take(towire_errorfmt(NULL,
extract_channel_id(msg, &channel_id) ? &channel_id : NULL,
"Unexpected message %s: %s",
wire_type_name(t),
tal_hex(tmpctx, msg))));
/* FIXME: We don't actually want master to try to send an
* error, since peer is transient. This is a hack.
*/
status_broken("Unexpected message %s", wire_type_name(t));
peer_failed_connection_lost();
}
static void handle_gossip_in(struct state *state)
{
u8 *msg = wire_sync_read(NULL, GOSSIP_FD);
if (!msg)
status_failed(STATUS_FAIL_GOSSIP_IO,
"Reading gossip: %s", strerror(errno));
handle_gossip_msg(PEER_FD, &state->cs, take(msg));
}
static bool is_all_channel_error(const u8 *msg)
{
struct channel_id channel_id;
u8 *data;
if (!fromwire_error(msg, msg, &channel_id, &data))
return false;
tal_free(data);
return channel_id_is_all(&channel_id);
}
static void fail_if_all_error(const u8 *inner)
{
if (!is_all_channel_error(inner))
return;
status_info("Master said send err: %s",
sanitize_error(tmpctx, inner, NULL));
exit(0);
}
static u8 *handle_master_in(struct state *state)
{
u8 *msg = wire_sync_read(tmpctx, REQ_FD);
enum opening_wire_type t = fromwire_peektype(msg);
u64 change_satoshis;
u32 change_keyindex;
u8 channel_flags;
struct utxo **utxos;
struct ext_key bip32_base;
switch (t) {
case WIRE_OPENING_FUNDER:
if (!fromwire_opening_funder(state, msg,
&state->funding_satoshis,
&state->push_msat,
&state->feerate_per_kw,
&change_satoshis, &change_keyindex,
&channel_flags, &utxos,
&bip32_base))
master_badmsg(WIRE_OPENING_FUNDER, msg);
msg = funder_channel(state,
change_satoshis,
change_keyindex, channel_flags,
utxos, &bip32_base);
return msg;
case WIRE_OPENING_CAN_ACCEPT_CHANNEL:
if (!fromwire_opening_can_accept_channel(msg))
master_badmsg(WIRE_OPENING_CAN_ACCEPT_CHANNEL, msg);
state->can_accept_channel = true;
return NULL;
case WIRE_OPENING_INIT:
case WIRE_OPENING_FUNDER_REPLY:
case WIRE_OPENING_FUNDEE:
case WIRE_OPENING_FUNDER_FAILED:
break;
}
status_failed(STATUS_FAIL_MASTER_IO,
"Unknown msg %s", tal_hex(tmpctx, msg));
}
int main(int argc, char *argv[])
{
setup_locale();
u8 *msg, *inner;
struct pollfd pollfd[3];
struct state *state = tal(NULL, struct state);
struct bitcoin_blkid chain_hash;
struct secret *none;
subdaemon_setup(argc, argv);
status_setup_sync(REQ_FD);
msg = wire_sync_read(tmpctx, REQ_FD);
if (!fromwire_opening_init(tmpctx, msg,
&chain_hash,
&state->localconf,
&state->max_to_self_delay,
&state->min_effective_htlc_capacity_msat,
&state->cs,
&state->our_points,
&state->our_funding_pubkey,
&state->minimum_depth,
&state->min_feerate, &state->max_feerate,
&state->can_accept_channel,
&inner))
master_badmsg(WIRE_OPENING_INIT, msg);
/* If they wanted to send an msg, do so before we waste time
* doing work. If it's a global error, we'll close
* immediately. */
if (inner != NULL) {
sync_crypto_write(&state->cs, PEER_FD, inner);
fail_if_all_error(inner);
}
state->chainparams = chainparams_by_chainhash(&chain_hash);
/* Initially we're not associated with a channel, but
* handle_peer_gossip_or_error wants this. */
memset(&state->channel_id, 0, sizeof(state->channel_id));
state->channel = NULL;
wire_sync_write(HSM_FD,
take(towire_hsm_get_per_commitment_point(NULL, 0)));
msg = wire_sync_read(tmpctx, HSM_FD);
if (!fromwire_hsm_get_per_commitment_point_reply(tmpctx, msg,
&state->next_per_commit[LOCAL],
&none))
status_failed(STATUS_FAIL_HSM_IO,
"Bad get_per_commitment_point_reply %s",
tal_hex(tmpctx, msg));
assert(none == NULL);
status_trace("Handed peer, entering loop");
pollfd[0].fd = REQ_FD;
pollfd[0].events = POLLIN;
pollfd[1].fd = GOSSIP_FD;
pollfd[1].events = POLLIN;
pollfd[2].fd = PEER_FD;
pollfd[2].events = POLLIN;
msg = NULL;
while (!msg) {
poll(pollfd, ARRAY_SIZE(pollfd), -1);
/* Subtle: handle_master_in can do its own poll loop, so
* don't try to service more than one fd per loop. */
if (pollfd[0].revents & POLLIN)
msg = handle_master_in(state);
else if (pollfd[2].revents & POLLIN)
msg = handle_peer_in(state);
else if (pollfd[1].revents & POLLIN)
handle_gossip_in(state);
clean_tmpctx();
}
/* Write message and hand back the fd. */
wire_sync_write(REQ_FD, msg);
fdpass_send(REQ_FD, PEER_FD);
fdpass_send(REQ_FD, GOSSIP_FD);
status_trace("Sent %s with fd",
opening_wire_type_name(fromwire_peektype(msg)));
tal_free(state);
daemon_shutdown();
return 0;
}
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