core-lightning/daemon/peer.h

#ifndef LIGHTNING_DAEMON_PEER_H
#define LIGHTNING_DAEMON_PEER_H
#include "config.h"
#include "bitcoin/locktime.h"
#include "bitcoin/privkey.h"
#include "bitcoin/pubkey.h"
#include "bitcoin/script.h"
#include "bitcoin/shadouble.h"
#include "channel.h"
#include "htlc.h"
#include "lightning.pb-c.h"
#include "netaddr.h"
#include "protobuf_convert.h"
#include "state.h"
#include <ccan/crypto/sha256/sha256.h>
#include <ccan/crypto/shachain/shachain.h>
#include <ccan/list/list.h>
#include <ccan/time/time.h>

struct anchor_input {
	struct sha256_double txid;
	unsigned int index;
	/* Amount of input (satoshis) */
	u64 amount;
	/* Wallet entry to use to spend. */
	struct wallet *w;
};

/* Information we remember for their commitment txs which we signed.
 *
 * Given the commit_num, we can use shachain to derive the revocation preimage
 * (if we've received it yet: we might have not, for the last).
 */
struct their_commit {
	struct list_node list;

	struct sha256_double txid;
	u64 commit_num;
};
	
struct commit_info {
	/* Commit number (0 == from open) */
	u64 commit_num;
	/* Revocation hash. */
	struct sha256 revocation_hash;
	/* Commit tx & txid */
	struct bitcoin_tx *tx;
	struct sha256_double txid;
	/* Channel state for this tx. */
	struct channel_state *cstate;
	/* Other side's signature for last commit tx (if known) */
	struct bitcoin_signature *sig;
	/* Order which commit was sent (theirs) / revocation was sent (ours) */
	s64 order;
};

struct peer_visible_state {
	/* CMD_OPEN_WITH_ANCHOR or CMD_OPEN_WITHOUT_ANCHOR */
	enum state_input offer_anchor;
	/* Key for commitment tx inputs, then key for commitment tx outputs */
	struct pubkey commitkey, finalkey;
	/* How long to they want the other's outputs locked (blocks) */
	struct rel_locktime locktime;
	/* Minimum depth of anchor before channel usable. */
	unsigned int mindepth;
	/* Commitment fee they're offering (satoshi). */
	u64 commit_fee_rate;
	/* Revocation hash for next commit tx. */
	struct sha256 next_revocation_hash;
	/* Commit txs: last one is current. */
	struct commit_info *commit;

	/* cstate to generate next commitment tx. */
	struct channel_state *staging_cstate;
};

/* Off peer->outgoing_txs */
struct outgoing_tx {
	struct list_node list;
	const struct bitcoin_tx *tx;
	struct sha256_double txid;
};

struct peer {
	/* dstate->peers list */
	struct list_node list;

	/* State in state machine. */
	enum state state;

	/* Network connection. */
	struct io_conn *conn;

	/* Are we connected now? (Crypto handshake completed). */
	bool connected;
	
	/* If we're doing a commit, this is the command which triggered it */
	struct command *commit_jsoncmd;

	/* Any outstanding "pay" commands. */
	struct list_head pay_commands;
	
	/* Global state. */
	struct lightningd_state *dstate;

	/* The other end's address. */
	struct netaddr addr;

	/* Their ID. */
	struct pubkey *id;

	/* Order counter for transmission of revocations/commitments. */
	s64 order_counter;
	
	/* Current received packet. */
	Pkt *inpkt;

	/* Queue of output packets. */
	Pkt **outpkt;

	/* Their commitments we have signed (which could appear on chain). */
	struct list_head their_commits;

	/* Number of commitment signatures we've received. */
	u64 their_commitsigs;
	
	/* Anchor tx output */
	struct {
		struct sha256_double txid;
		unsigned int index;
		u64 satoshis;
		u8 *witnessscript;

		/* Minimum possible depth for anchor */
		unsigned int min_depth;

		/* If we're creating anchor, this tells us where to source it */
		struct anchor_input *input;
	
		/* If we created it, we keep entire tx. */
		const struct bitcoin_tx *tx;

		/* Depth to trigger anchor if still opening, or -1. */
		int ok_depth;

		/* Did we create anchor? */
		bool ours;
	} anchor;

	struct {
		/* Their signature for our current commit sig. */
		struct bitcoin_signature theirsig;
		/* The watch we have on a live commit tx. */
		struct txwatch *watch;
	} cur_commit;

	/* Counter to make unique HTLC ids. */
	u64 htlc_id_counter;

	/* Mutual close info. */
	struct {
		/* Our last suggested closing fee. */
		u64 our_fee;
		/* If they've offered a signature, these are set: */
		struct bitcoin_signature *their_sig;
		/* If their_sig is non-NULL, this is the fee. */
		u64 their_fee;
		/* scriptPubKey we/they want for closing. */
		u8 *our_script, *their_script;
		/* Last sent (in case we need to retransmit) */
		s64 shutdown_order, closing_order;
		/* How many closing sigs have we receieved? */
		u32 sigs_in;
	} closing;

	/* If we're closing on-chain */
	struct {
		/* Everything (watches, resolved[], etc) tal'ed off this:
		 * The commit which spends the anchor tx. */
		const struct bitcoin_tx *tx;
		struct sha256_double txid;

		/* If >= 0, indicates which txout is to us and to them. */
		int to_us_idx, to_them_idx;
		/* Maps what txouts are HTLCs (NULL implies to_us/them_idx). */
		struct htlc **htlcs;
		/* Witness scripts for each output (where appropriate) */
		const u8 **wscripts;
		/* The tx which resolves each txout. */
		const struct bitcoin_tx **resolved;
	} onchain;

	/* All HTLCs. */
	struct htlc_map htlcs;

	/* Current ongoing packetflow */
	struct io_data *io_data;
	
	/* What happened. */
	struct log *log;

	/* Things we're watching for (see watches.c) */
	struct list_head watches;

	/* Bitcoin transctions we're broadcasting (see chaintopology.c) */
	struct list_head outgoing_txs;
	
	/* Timeout for collecting changes before sending commit. */
	struct oneshot *commit_timer;
	
	/* Private keys for dealing with this peer. */
	struct peer_secrets *secrets;

	/* Our route connection to peer: NULL until we are in normal mode. */
	struct node_connection *nc;
	
	/* For testing. */
	bool fake_close;
	bool output_enabled;

	/* Stuff we have in common. */
	struct peer_visible_state local, remote;

	/* If we have sent a new commit tx, but not received their revocation */
	struct sha256 *their_prev_revocation_hash;
	
	/* this is where we will store their revocation preimages*/
	struct shachain their_preimages;
};

void setup_listeners(struct lightningd_state *dstate, unsigned int portnum);

struct peer *find_peer(struct lightningd_state *dstate, const struct pubkey *id);

struct peer *new_peer(struct lightningd_state *dstate,
		      enum state state,
		      enum state_input offer_anchor);

void set_htlc_rval(struct peer *peer,
		   struct htlc *htlc, const struct rval *rval);

/* Populates very first peer->{local,remote}.commit->{tx,cstate} */
bool setup_first_commit(struct peer *peer);

/* Whenever we send a signature, remember the txid -> commit_num mapping */
bool peer_add_their_commit(struct peer *peer,
			   const struct sha256_double *txid, u64 commit_num);

/* Allocate a new commit_info struct. */
struct commit_info *new_commit_info(const tal_t *ctx, u64 commit_num);

/* Freeing removes from map, too */
struct htlc *peer_new_htlc(struct peer *peer, 
			   u64 id,
			   u64 msatoshis,
			   const struct sha256 *rhash,
			   u32 expiry,
			   const u8 *route,
			   size_t route_len,
			   struct htlc *src,
			   enum htlc_state state);

struct htlc *command_htlc_add(struct peer *peer, u64 msatoshis,
			      unsigned int expiry,
			      const struct sha256 *rhash,
			      struct htlc *src,
			      const u8 *route);

void peer_unexpected_pkt(struct peer *peer, const Pkt *pkt, const char *where);

/* Peer has completed open, or problem (if non-NULL). */
void peer_open_complete(struct peer *peer, const char *problem);

struct bitcoin_tx *peer_create_close_tx(struct peer *peer, u64 fee);

void debug_dump_peers(struct lightningd_state *dstate);

void reconnect_peers(struct lightningd_state *dstate);
void cleanup_peers(struct lightningd_state *dstate);
#endif /* LIGHTNING_DAEMON_PEER_H */