daemon: newhtlc command.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

daemon/jsonrpc.c

@@ -238,6 +238,7 @@ static const struct json_command *cmdlist[] = {
 	&getlog_command,
 	&connect_command,
 	&getpeers_command,
+	&newhtlc_command,
 	/* Developer/debugging options. */
 	&echo_command,
 	&rhash_command,

daemon/jsonrpc.h

@@ -58,5 +58,5 @@ void setup_jsonrpc(struct lightningd_state *dstate, const char *rpc_filename);
 /* Commands (from other files) */
 extern const struct json_command connect_command;
 extern const struct json_command getpeers_command;
-
+extern const struct json_command newhtlc_command;
 #endif /* LIGHTNING_DAEMON_JSONRPC_H */

daemon/packets.c

@@ -11,6 +11,8 @@
 #include <ccan/crypto/sha256/sha256.h>
 #include <ccan/mem/mem.h>
 #include <ccan/str/hex/hex.h>
+#include <ccan/structeq/structeq.h>
+#include <inttypes.h>
 
 #define FIXME_STUB(peer) do { log_broken((peer)->dstate->base_log, "%s:%u: Implement %s!", __FILE__, __LINE__, __func__); abort(); } while(0)
 
@@ -99,7 +101,7 @@ Pkt *pkt_anchor(const tal_t *ctx, const struct peer *peer)
 	a->amount = peer->anchor.satoshis;
 
 	/* Sign their commit sig */
-	peer_sign_theircommit(peer, &sig);
+	peer_sign_theircommit(peer, peer->them.commit, &sig);
 	a->commit_sig = signature_to_proto(a, &sig);
 
 	return make_pkt(ctx, PKT__PKT_OPEN_ANCHOR, a);
@@ -115,7 +117,7 @@ Pkt *pkt_open_commit_sig(const tal_t *ctx, const struct peer *peer)
 	dump_tx("Creating sig for:", peer->them.commit);
 	dump_key("Using key:", &peer->us.commitkey);
 
-	peer_sign_theircommit(peer, &sig);
+	peer_sign_theircommit(peer, peer->them.commit, &sig);
 	s->sig = signature_to_proto(s, &sig);
 
 	return make_pkt(ctx, PKT__PKT_OPEN_COMMIT_SIG, s);
@@ -132,7 +134,16 @@ Pkt *pkt_open_complete(const tal_t *ctx, const struct peer *peer)
 Pkt *pkt_htlc_update(const tal_t *ctx, const struct peer *peer,
 		     const struct htlc_progress *htlc_prog)
 {
-	FIXME_STUB(peer);
+	UpdateAddHtlc *u = tal(ctx, UpdateAddHtlc);
+
+	update_add_htlc__init(u);
+
+	u->revocation_hash = sha256_to_proto(u, &htlc_prog->our_revocation_hash);
+	u->amount_msat = htlc_prog->msatoshis;
+	u->r_hash = sha256_to_proto(u, &htlc_prog->rhash);
+	u->expiry = abs_locktime_to_proto(u, &htlc_prog->expiry);
+
+	return make_pkt(ctx, PKT__PKT_UPDATE_ADD_HTLC, u);
 }
 
 Pkt *pkt_htlc_fulfill(const tal_t *ctx, const struct peer *peer,
@@ -155,17 +166,50 @@ Pkt *pkt_htlc_routefail(const tal_t *ctx, const struct peer *peer,
 
 Pkt *pkt_update_accept(const tal_t *ctx, const struct peer *peer)
 {
-	FIXME_STUB(peer);
+	UpdateAccept *u = tal(ctx, UpdateAccept);
+	const struct htlc_progress *cur = peer->current_htlc;
+	struct signature sig;
+
+	update_accept__init(u);
+
+	dump_tx("Signing tx", cur->their_commit);
+	peer_sign_theircommit(peer, cur->their_commit, &sig);
+	u->sig = signature_to_proto(u, &sig);
+	u->revocation_hash
+		= sha256_to_proto(u, &cur->our_revocation_hash);
+
+	return make_pkt(ctx, PKT__PKT_UPDATE_ACCEPT, u);
 }
 
 Pkt *pkt_update_signature(const tal_t *ctx, const struct peer *peer)
 {
-	FIXME_STUB(peer);
+	UpdateSignature *u = tal(ctx, UpdateSignature);
+	const struct htlc_progress *cur = peer->current_htlc;
+	struct signature sig;
+	struct sha256 preimage;
+
+	update_signature__init(u);
+
+	peer_sign_theircommit(peer, cur->their_commit, &sig);
+	u->sig = signature_to_proto(u, &sig);
+	assert(peer->num_htlcs > 0);
+	peer_get_revocation_preimage(peer, peer->num_htlcs-1, &preimage);
+	u->revocation_preimage = sha256_to_proto(u, &preimage);
+
+	return make_pkt(ctx, PKT__PKT_UPDATE_SIGNATURE, u);
 }
 
 Pkt *pkt_update_complete(const tal_t *ctx, const struct peer *peer)
 {
-	FIXME_STUB(peer);
+	UpdateComplete *u = tal(ctx, UpdateComplete);
+	struct sha256 preimage;
+
+	update_complete__init(u);
+
+	peer_get_revocation_preimage(peer, peer->num_htlcs-1, &preimage);
+	u->revocation_preimage = sha256_to_proto(u, &preimage);
+
+	return make_pkt(ctx, PKT__PKT_UPDATE_COMPLETE, u);
 }
 
 Pkt *pkt_err(const tal_t *ctx, const char *msg, ...)
@@ -317,8 +361,49 @@ Pkt *accept_pkt_htlc_update(const tal_t *ctx,
 			    struct peer *peer, const Pkt *pkt,
 			    Pkt **decline)
 {
-	FIXME_STUB(peer);
-}
+	const UpdateAddHtlc *u = pkt->update_add_htlc;
+	struct htlc_progress *cur = tal(peer, struct htlc_progress);
+	Pkt *err;
+
+	cur->msatoshis = u->amount_msat;
+	proto_to_sha256(u->r_hash, &cur->rhash);
+	proto_to_sha256(u->revocation_hash, &cur->their_revocation_hash);
+	if (!proto_to_abs_locktime(u->expiry, &cur->expiry)) {
+		err = pkt_err(ctx, "Invalid HTLC expiry");
+		goto fail;
+	}
+	cur->cstate = copy_funding(cur, peer->cstate);
+	if (!funding_delta(peer->them.offer_anchor == CMD_OPEN_WITH_ANCHOR,
+			   peer->anchor.satoshis,
+			   0, cur->msatoshis,
+			   &cur->cstate->b, &cur->cstate->a)) {
+		err = pkt_err(ctx, "Cannot afford %"PRIu64" milli-satoshis",
+			      cur->msatoshis);
+		goto fail;
+	}
+	/* Add the htlc to their side of channel. */
+	funding_add_htlc(&cur->cstate->b, cur->msatoshis,
+			 &cur->expiry, &cur->rhash);
+	
+	peer_get_revocation_hash(peer, peer->num_htlcs+1,
+				 &cur->our_revocation_hash);
+
+	/* Now we create the commit tx pair. */
+	make_commit_txs(cur, peer, &cur->our_revocation_hash,
+			&cur->their_revocation_hash,
+			cur->cstate,
+			&cur->our_commit, &cur->their_commit);
+
+	/* FIXME: Fees must be sufficient. */
+	*decline = NULL;
+	assert(!peer->current_htlc);
+	peer->current_htlc = cur;
+	return NULL;
+
+fail:
+	tal_free(cur);
+	return err;
+};
 
 Pkt *accept_pkt_htlc_routefail(const tal_t *ctx,
 			       struct peer *peer, const Pkt *pkt)
@@ -338,23 +423,124 @@ Pkt *accept_pkt_htlc_fulfill(const tal_t *ctx,
 	FIXME_STUB(peer);
 }
 
+static u64 total_funds(const struct channel_oneside *c)
+{
+	u64 total = (u64)c->pay_msat + c->fee_msat;
+	size_t i, n = tal_count(c->htlcs);
+
+	for (i = 0; i < n; i++)
+		total += c->htlcs[i].msatoshis;
+	return total;
+}
+
+static void update_to_new_htlcs(struct peer *peer)
+{
+	struct htlc_progress *cur = peer->current_htlc;
+
+	/* FIXME: Add to shachain too. */
+
+	/* HTLCs can't change total balance in channel! */
+	if (total_funds(&peer->cstate->a) + total_funds(&peer->cstate->b)
+	    != total_funds(&cur->cstate->a) + total_funds(&cur->cstate->b))
+		fatal("Illegal funding transition from %u/%u (total %"PRIu64")"
+		      " to %u/%u (total %"PRIu64")",
+		      peer->cstate->a.pay_msat, peer->cstate->a.fee_msat,
+		      total_funds(&peer->cstate->a),
+		      peer->cstate->b.pay_msat, peer->cstate->b.fee_msat,
+		      total_funds(&peer->cstate->b));
+
+	/* Now, we consider this channel_state current one. */
+	tal_free(peer->cstate);
+	peer->cstate = tal_steal(peer, cur->cstate);
+
+	tal_free(peer->us.commit);
+	peer->us.commit = tal_steal(peer, cur->our_commit);
+	/* FIXME: Save their old commit details, to steal funds. */
+	tal_free(peer->them.commit);
+	peer->them.commit = tal_steal(peer, cur->their_commit);
+	peer->us.revocation_hash = cur->our_revocation_hash;
+	peer->them.revocation_hash = cur->their_revocation_hash;
+
+	peer->num_htlcs++;
+}
+
 Pkt *accept_pkt_update_accept(const tal_t *ctx,
 			      struct peer *peer, const Pkt *pkt)
 {
-	FIXME_STUB(peer);
+	const UpdateAccept *a = pkt->update_accept;
+	struct htlc_progress *cur = peer->current_htlc;
+	
+	proto_to_sha256(a->revocation_hash, &cur->their_revocation_hash);
+
+	cur->their_sig.stype = SIGHASH_ALL;
+	if (!proto_to_signature(a->sig, &cur->their_sig.sig))
+		return pkt_err(ctx, "Malformed signature");
+
+	/* Now we can make commit tx pair. */
+	make_commit_txs(cur, peer, &cur->our_revocation_hash,
+			&cur->their_revocation_hash,
+			cur->cstate,
+			&cur->our_commit, &cur->their_commit);
+
+	/* Their sig should sign our new commit tx. */
+	if (!check_tx_sig(peer->dstate->secpctx,
+			  cur->our_commit, 0,
+			  peer->anchor.redeemscript,
+			  tal_count(peer->anchor.redeemscript),
+			  &peer->them.commitkey,
+			  &cur->their_sig))
+		return pkt_err(ctx, "Bad signature");
+
+	/* Our next step will be to send the revocation preimage, so
+	 * update to new HTLC now so we never use the old one. */
+	update_to_new_htlcs(peer);
+	return NULL;
+}	
+
+static bool check_preimage(const Sha256Hash *preimage, const struct sha256 *hash)
+{
+	struct sha256 h;
+
+	proto_to_sha256(preimage, &h);
+	sha256(&h, &h, sizeof(h));
+	return structeq(&h, hash);
 }
 
 Pkt *accept_pkt_update_complete(const tal_t *ctx,
 				struct peer *peer, const Pkt *pkt)
 {
-	FIXME_STUB(peer);
+	/* FIXME: Check preimage against old tx! */
+	return NULL;
 }
 
 Pkt *accept_pkt_update_signature(const tal_t *ctx,
 				 struct peer *peer,
 				 const Pkt *pkt)
 {
-	FIXME_STUB(peer);
+	const UpdateSignature *s = pkt->update_signature;
+	struct htlc_progress *cur = peer->current_htlc;
+
+	cur->their_sig.stype = SIGHASH_ALL;
+	if (!proto_to_signature(s->sig, &cur->their_sig.sig))
+		return pkt_err(ctx, "Malformed signature");
+
+	/* Their sig should sign our new commit tx. */
+	if (!check_tx_sig(peer->dstate->secpctx,
+			  cur->our_commit, 0,
+			  peer->anchor.redeemscript,
+			  tal_count(peer->anchor.redeemscript),
+			  &peer->them.commitkey,
+			  &cur->their_sig))
+		return pkt_err(ctx, "Bad signature");
+
+	/* Check their revocation preimage. */
+	if (!check_preimage(s->revocation_preimage, &peer->them.revocation_hash))
+		return pkt_err(ctx, "Bad revocation preimage");
+
+	/* Our next step will be to send the revocation preimage, so
+	 * update to new HTLC now so we never use the old one. */
+	update_to_new_htlcs(peer);
+	return NULL;
 }
 
 Pkt *accept_pkt_close(const tal_t *ctx, struct peer *peer, const Pkt *pkt)

daemon/peer.c

@@ -17,10 +17,12 @@
 #include <ccan/io/io.h>
 #include <ccan/list/list.h>
 #include <ccan/noerr/noerr.h>
+#include <ccan/str/hex/hex.h>
 #include <ccan/structeq/structeq.h>
 #include <ccan/tal/str/str.h>
 #include <ccan/tal/tal.h>
 #include <errno.h>
+#include <inttypes.h>
 #include <netinet/in.h>
 #include <stdlib.h>
 #include <sys/socket.h>
@@ -35,6 +37,17 @@ struct json_connecting {
 	u64 satoshis;
 };
 
+static struct peer *find_peer(struct lightningd_state *dstate,
+			      const struct pubkey *id)
+{
+	struct peer *peer;
+	list_for_each(&dstate->peers, peer, list) {
+		if (peer->state != STATE_INIT && pubkey_eq(&peer->id, id))
+			return peer;
+	}
+	return NULL;
+}
+
 static void queue_output_pkt(struct peer *peer, Pkt *pkt)
 {
 	peer->outpkt[peer->num_outpkt++] = pkt;
@@ -236,6 +249,8 @@ static struct peer *new_peer(struct lightningd_state *dstate,
 	list_head_init(&peer->watches);
 	peer->num_outpkt = 0;
 	peer->cmd = INPUT_NONE;
+	peer->current_htlc = NULL;
+	peer->num_htlcs = 0;
 
 	/* If we free peer, conn should be closed, but can't be freed
 	 * immediately so don't make peer a parent. */
@@ -622,7 +637,7 @@ void peer_htlc_ours_deferred(struct peer *peer)
 /* Successfully added/fulfilled/timedout/routefail an HTLC. */
 void peer_htlc_done(struct peer *peer)
 {
-	FIXME_STUB(peer);
+	peer->current_htlc = tal_free(peer->current_htlc);
 }
 
 /* Someone aborted an existing HTLC. */
@@ -898,3 +913,98 @@ const struct json_command getpeers_command = {
 	"List the current peers",
 	"Returns a 'peers' array"
 };
+
+static void json_newhtlc(struct command *cmd,
+			 const char *buffer, const jsmntok_t *params)
+{
+	struct peer *peer;
+	jsmntok_t *idtok, *msatoshistok, *expirytok, *rhashtok;
+	struct pubkey id;
+	unsigned int expiry;
+	struct htlc_progress *cur;
+
+	json_get_params(buffer, params,
+			"id", &idtok,
+			"msatoshis", &msatoshistok,
+			"expiry", &expirytok,
+			"rhash", &rhashtok,
+			NULL);
+
+	if (!idtok || !msatoshistok || !expirytok || !rhashtok) {
+		command_fail(cmd, "Need id, msatoshis, expiry and rhash");
+		return;
+	}
+
+	if (!pubkey_from_hexstr(cmd->dstate->secpctx,
+				buffer + idtok->start,
+				idtok->end - idtok->start, &id)) {
+		command_fail(cmd, "Not a valid id");
+		return;
+	}
+	peer = find_peer(cmd->dstate, &id);
+	if (!peer) {
+		command_fail(cmd, "Could not find peer with that id");
+		return;
+	}
+
+	/* Attach to cmd until it's complete. */
+	cur = tal(cmd, struct htlc_progress);
+	if (!json_tok_u64(buffer, msatoshistok, &cur->msatoshis)) {
+		command_fail(cmd, "'%.*s' is not a valid number",
+			     (int)(msatoshistok->end - msatoshistok->start),
+			     buffer + msatoshistok->start);
+		return;
+	}
+	if (!json_tok_number(buffer, expirytok, &expiry)) {
+		command_fail(cmd, "'%.*s' is not a valid number",
+			     (int)(expirytok->end - expirytok->start),
+			     buffer + expirytok->start);
+		return;
+	}
+
+	if (!seconds_to_abs_locktime(expiry, &cur->expiry)) {
+		command_fail(cmd, "'%.*s' is not a valid number",
+			     (int)(expirytok->end - expirytok->start),
+			     buffer + expirytok->start);
+		return;
+	}
+	if (!hex_decode(buffer + rhashtok->start,
+			rhashtok->end - rhashtok->start,
+			&cur->rhash, sizeof(cur->rhash))) {
+		command_fail(cmd, "'%.*s' is not a valid sha256 hash",
+			     (int)(rhashtok->end - rhashtok->start),
+			     buffer + rhashtok->start);
+		return;
+	}
+	peer_get_revocation_hash(peer, peer->num_htlcs+1,
+				 &cur->our_revocation_hash);
+
+	/* Can we even offer this much? */
+	cur->cstate = copy_funding(cur, peer->cstate);
+	if (!funding_delta(peer->us.offer_anchor == CMD_OPEN_WITH_ANCHOR,
+			   peer->anchor.satoshis,
+			   0, cur->msatoshis,
+			   &cur->cstate->a, &cur->cstate->b)) {
+		command_fail(cmd, "Cannot afford %"PRIu64" milli-satoshis",
+			     cur->msatoshis);
+		return;
+	}
+	/* Add the htlc to our side of channel. */
+	funding_add_htlc(&cur->cstate->a, cur->msatoshis,
+			 &cur->expiry, &cur->rhash);
+
+	peer->current_htlc = tal_steal(peer, cur);
+	peer->jsoncmd = cmd;
+
+	/* FIXME: do we need this? */
+	peer->cmddata.htlc_prog = peer->current_htlc;
+	peer->cmd = CMD_SEND_HTLC_UPDATE;
+	try_command(peer);
+}
+
+const struct json_command newhtlc_command = {
+	"newhtlc",
+	json_newhtlc,
+	"Offer {id} an HTLC worth {msatoshis} in {expiry} (in seconds since Jan 1 1970) with {rhash}",
+	"Returns an empty result on success"
+};

daemon/peer.h

@@ -29,6 +29,17 @@ struct peer_visible_state {
 	struct bitcoin_tx *commit;
 };
 
+struct htlc_progress {
+	/* Channel funding state, after we've completed htlc. */
+	struct channel_state *cstate;
+	struct abs_locktime expiry;
+	u64 msatoshis;
+	struct sha256 rhash;
+	struct sha256 our_revocation_hash, their_revocation_hash;
+	struct bitcoin_tx *our_commit, *their_commit;
+	struct bitcoin_signature their_sig;
+};
+
 struct peer {
 	/* dstate->peers list */
 	struct list_node list;
@@ -79,6 +90,11 @@ struct peer {
 	/* Their signature for our current commit sig. */
 	struct bitcoin_signature cur_commit_theirsig;
 
+	/* Current HTLC, if any. */
+	struct htlc_progress *current_htlc;
+	/* Number of HTLC updates (== number of previous commit txs) */
+	u64 num_htlcs;
+	
 	/* Current ongoing packetflow */
 	struct io_data *io_data;
 	

daemon/secrets.c

@@ -41,11 +41,13 @@ struct peer_secrets {
 	struct sha256 revocation_seed;
 };
 
-void peer_sign_theircommit(const struct peer *peer, struct signature *sig)
+void peer_sign_theircommit(const struct peer *peer,
+			   struct bitcoin_tx *commit,
+			   struct signature *sig)
 {
 	/* Commit tx only has one input: that of the anchor. */
 	sign_tx_input(peer->dstate->secpctx,
-		      peer->them.commit, 0,
+		      commit, 0,
 		      peer->anchor.redeemscript,
 		      tal_count(peer->anchor.redeemscript),
 		      &peer->secrets->commit,

daemon/secrets.h

@@ -12,7 +12,9 @@ struct sha256;
 void privkey_sign(struct peer *peer, const void *src, size_t len,
 		  struct signature *sig);
 
-void peer_sign_theircommit(const struct peer *peer, struct signature *sig);
+void peer_sign_theircommit(const struct peer *peer,
+			   struct bitcoin_tx *commit,
+			   struct signature *sig);
 
 void peer_secrets_init(struct peer *peer);
 

daemon/test/test.sh

@@ -53,6 +53,9 @@ while ! $LCLI2 getlog | grep 'listener on port'; do
     fi
 done
 
+ID1=`$LCLI1 getlog | sed -n 's/.*"ID: \([0-9a-f]*\)".*/\1/p'`
+ID2=`$LCLI2 getlog | sed -n 's/.*"ID: \([0-9a-f]*\)".*/\1/p'`
+
 PORT2=`$LCLI2 getlog | sed -n 's/.*on port \([0-9]*\).*/\1/p'`
 
 $LCLI1 connect localhost $PORT2 999999
@@ -71,6 +74,11 @@ sleep 2
 $LCLI1 getpeers | grep STATE_NORMAL_HIGHPRIO
 $LCLI2 getpeers | grep STATE_NORMAL_LOWPRIO
 
+EXPIRY=$(( $(date +%s) + 1000))
+SECRET=1de08917a61cb2b62ed5937d38577f6a7bfe59c176781c6d8128018e8b5ccdfd
+RHASH=`$LCLI1 dev-rhash $SECRET | sed 's/.*"\([0-9a-f]*\)".*/\1/'`
+$LCLI1 newhtlc $ID2 1000000 $EXPIRY $RHASH
+
 $LCLI1 stop
 $LCLI2 stop
 scripts/shutdown.sh