daemon: pay command.

This is the command an actual user would use: it figures out the fee
and route, and pays it if it can.

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

daemon/Makefile

@@ -25,9 +25,10 @@ DAEMON_SRC :=					\
 	daemon/netaddr.c			\
 	daemon/onion.c				\
 	daemon/opt_time.c			\
-	daemon/peer.c				\
 	daemon/packets.c			\
+	daemon/pay.c				\
 	daemon/payment.c			\
+	daemon/peer.c				\
 	daemon/routing.c			\
 	daemon/secrets.c			\
 	daemon/timeout.c			\
@@ -60,6 +61,7 @@ DAEMON_HEADERS :=				\
 	daemon/netaddr.h			\
 	daemon/onion.h				\
 	daemon/opt_time.h			\
+	daemon/pay.h				\
 	daemon/payment.h			\
 	daemon/peer.h				\
 	daemon/pseudorand.h			\

daemon/chaintopology.h

@@ -1,9 +1,13 @@
 #ifndef LIGHTNING_DAEMON_CHAINTOPOLOGY_H
 #define LIGHTNING_DAEMON_CHAINTOPOLOGY_H
 #include "config.h"
+#include <ccan/short_types/short_types.h>
 #include <stddef.h>
 
+struct bitcoin_tx;
 struct lightningd_state;
+struct peer;
+struct sha256_double;
 struct txwatch;
 
 /* This is the number of blocks which would have to be mined to invalidate

daemon/jsonrpc.c

@@ -256,6 +256,7 @@ static const struct json_command *cmdlist[] = {
 	&close_command,
 	&newaddr_command,
 	&accept_payment_command,
+	&pay_command,
 	/* Developer/debugging options. */
 	&echo_command,
 	&rhash_command,

daemon/jsonrpc.h

@@ -72,4 +72,5 @@ extern const struct json_command output_command;
 extern const struct json_command accept_payment_command;
 extern const struct json_command add_route_command;
 extern const struct json_command routefail_command;
+extern const struct json_command pay_command;
 #endif /* LIGHTNING_DAEMON_JSONRPC_H */

daemon/pay.c

@@ -0,0 +1,139 @@
+#include "chaintopology.h"
+#include "jsonrpc.h"
+#include "lightningd.h"
+#include "log.h"
+#include "onion.h"
+#include "pay.h"
+#include "peer.h"
+#include "routing.h"
+#include <ccan/str/hex/hex.h>
+#include <inttypes.h>
+
+/* Outstanding "pay" commands. */
+struct pay_command {
+	struct list_node list;
+	struct htlc *htlc;
+	struct command *cmd;
+};
+
+void complete_pay_command(struct peer *peer,
+			  struct htlc *htlc,
+			  const struct rval *rval)
+{
+	struct pay_command *i;
+
+	list_for_each(&peer->pay_commands, i, list) {
+		if (i->htlc == htlc) {
+			if (rval) {
+				struct json_result *response;
+
+				response = new_json_result(i->cmd);	
+				json_object_start(response, NULL);
+				json_add_hex(response, "preimage",
+					     rval->r, sizeof(rval->r));
+				json_object_end(response);
+				command_success(i->cmd, response);
+			} else {
+				command_fail(i->cmd, "htlc failed");
+			}
+			return;
+		}
+	}
+	/* Can happen if RPC connection goes away. */
+	log_unusual(peer->log, "No command for HTLC %"PRIu64" %s",
+		    htlc->id, rval ? "fulfill" : "fail");
+}		
+
+static void remove_from_list(struct pay_command *pc)
+{
+	list_del(&pc->list);
+}
+
+static void json_pay(struct command *cmd,
+		     const char *buffer, const jsmntok_t *params)
+{
+	struct pubkey id;
+	jsmntok_t *idtok, *msatoshistok, *rhashtok;
+	unsigned int expiry;
+	int i;
+	u64 msatoshis;
+	s64 fee;
+	struct sha256 rhash;
+	struct node_connection **route;
+	struct peer *peer;
+	struct pay_command *pc;
+	const u8 *onion;
+
+	if (!json_get_params(buffer, params,
+			     "id", &idtok,
+			     "msatoshis", &msatoshistok,
+			     "rhash", &rhashtok,
+			     NULL)) {
+		command_fail(cmd, "Need id, msatoshis and rhash");
+		return;
+	}
+
+	if (!pubkey_from_hexstr(cmd->dstate->secpctx,
+				buffer + idtok->start,
+				idtok->end - idtok->start, &id)) {
+		command_fail(cmd, "Invalid id");
+		return;
+	}
+
+	if (!json_tok_u64(buffer, msatoshistok, &msatoshis)) {
+		command_fail(cmd, "'%.*s' is not a valid number",
+			     (int)(msatoshistok->end - msatoshistok->start),
+			     buffer + msatoshistok->start);
+		return;
+	}
+
+	if (!hex_decode(buffer + rhashtok->start,
+			rhashtok->end - rhashtok->start,
+			&rhash, sizeof(rhash))) {
+		command_fail(cmd, "'%.*s' is not a valid sha256 hash",
+			     (int)(rhashtok->end - rhashtok->start),
+			     buffer + rhashtok->start);
+		return;
+	}
+
+	/* FIXME: Add fee param, check for excessive fee. */
+	peer = find_route(cmd->dstate, &id, msatoshis, &fee, &route);
+	if (!peer) {
+		command_fail(cmd, "no route found");
+		return;
+	}
+
+	expiry = 0;
+	for (i = tal_count(route) - 1; i >= 0; i--) {
+		expiry += route[i]->delay;
+		if (expiry < route[i]->min_blocks)
+			expiry = route[i]->min_blocks;
+	}
+	expiry += peer->nc->delay;
+	if (expiry < peer->nc->min_blocks)
+		expiry = peer->nc->min_blocks;
+
+	/* Expiry for HTLCs is absolute.  And add one to give some margin. */
+	expiry += get_block_height(cmd->dstate) + 1;
+
+	onion = onion_create(cmd, route, msatoshis, fee);
+	pc = tal(cmd, struct pay_command);
+	pc->cmd = cmd;
+	pc->htlc = command_htlc_add(peer, msatoshis + fee, expiry, &rhash, NULL,
+				    onion);
+	if (!pc->htlc) {
+		command_fail(cmd, "could not add htlc");
+		return;
+	}
+
+	/* Wait until we get response. */
+	list_add_tail(&peer->pay_commands, &pc->list);
+	tal_add_destructor(pc, remove_from_list);
+}
+
+const struct json_command pay_command = {
+	"pay",
+	json_pay,
+	"Send {id} {msatoshis} in return for preimage of {rhash}",
+	"Returns an empty result on success"
+};

daemon/pay.h

@@ -0,0 +1,13 @@
+#ifndef LIGHTNING_DAEMON_PAY_H
+#define LIGHTNING_DAEMON_PAY_H
+#include "config.h"
+
+struct peer;
+struct htlc;
+struct rval;
+
+void complete_pay_command(struct peer *peer,
+			  struct htlc *htlc,
+			  const struct rval *rval);
+
+#endif /* LIGHTNING_DAEMON_PAY_H */

daemon/peer.c

@@ -11,6 +11,7 @@
 #include "log.h"
 #include "names.h"
 #include "onion.h"
+#include "pay.h"
 #include "payment.h"
 #include "peer.h"
 #include "permute_tx.h"
@@ -567,11 +568,11 @@ static bool command_htlc_fulfill(struct peer *peer,
 	return true;
 }
 
-static bool command_htlc_add(struct peer *peer, u64 msatoshis,
-			     unsigned int expiry,
-			     const struct sha256 *rhash,
-			     struct htlc *src,
-			     const u8 *route)
+struct htlc *command_htlc_add(struct peer *peer, u64 msatoshis,
+			      unsigned int expiry,
+			      const struct sha256 *rhash,
+			      struct htlc *src,
+			      const u8 *route)
 {
 	struct channel_state *cstate;
 	struct abs_locktime locktime;
@@ -579,19 +580,19 @@ static bool command_htlc_add(struct peer *peer, u64 msatoshis,
 
 	if (!blocks_to_abs_locktime(expiry, &locktime)) {
 		log_unusual(peer->log, "add_htlc: fail: bad expiry %u", expiry);
-		return false;
+		return NULL;
 	}
 
 	if (expiry < get_block_height(peer->dstate) + peer->dstate->config.min_htlc_expiry) {
 		log_unusual(peer->log, "add_htlc: fail: expiry %u is too soon",
 			    expiry);
-		return false;
+		return NULL;
 	}
 
 	if (expiry > get_block_height(peer->dstate) + peer->dstate->config.max_htlc_expiry) {
 		log_unusual(peer->log, "add_htlc: fail: expiry %u is too far",
 			    expiry);
-		return false;
+		return NULL;
 	}
 
 	/* FIXME: This is wrong: constraint on remote is sufficient. */
@@ -603,13 +604,13 @@ static bool command_htlc_add(struct peer *peer, u64 msatoshis,
 	if (tal_count(peer->local.staging_cstate->side[OURS].htlcs) == 300
 	    || tal_count(peer->remote.staging_cstate->side[OURS].htlcs) == 300) {
 		log_unusual(peer->log, "add_htlc: fail: already at limit");
-		return false;
+		return NULL;
 	}
 
 	if (!state_can_add_htlc(peer->state)) {
 		log_unusual(peer->log, "add_htlc: fail: peer state %s",
 			    state_name(peer->state));
-		return false;
+		return NULL;
 	}
 
 	htlc = peer_new_htlc(peer, peer->htlc_id_counter,
@@ -628,8 +629,7 @@ static bool command_htlc_add(struct peer *peer, u64 msatoshis,
 		log_unusual(peer->log, "add_htlc: fail: Cannot afford %"PRIu64
 			    " milli-satoshis in their commit tx",
 			    msatoshis);
-		tal_free(htlc);
-		return false;
+		return tal_free(htlc);
 	}
 	tal_free(cstate);
 
@@ -638,8 +638,7 @@ static bool command_htlc_add(struct peer *peer, u64 msatoshis,
 		log_unusual(peer->log, "add_htlc: fail: Cannot afford %"PRIu64
 			    " milli-satoshis in our commit tx",
 			    msatoshis);
-		tal_free(htlc);
-		return false;
+		return tal_free(htlc);
 	}
 	tal_free(cstate);
 
@@ -648,7 +647,7 @@ static bool command_htlc_add(struct peer *peer, u64 msatoshis,
 	/* Make sure we never offer the same one twice. */
 	peer->htlc_id_counter++;
 
-	return true;
+	return htlc;
 }
 
 static struct io_plan *pkt_out(struct io_conn *conn, struct peer *peer)
@@ -658,8 +657,10 @@ static struct io_plan *pkt_out(struct io_conn *conn, struct peer *peer)
 
 	if (n == 0) {
 		/* We close the connection once we've sent everything. */
-		if (!state_can_io(peer->state))
+		if (!state_can_io(peer->state)) {
+			log_debug(peer->log, "pkt_out: no IO possible, closing");
 			return io_close(conn);
+		}
 		return io_out_wait(conn, peer, pkt_out, peer);
 	}
 
@@ -825,6 +826,7 @@ static struct peer *new_peer(struct lightningd_state *dstate,
 	peer->outpkt = tal_arr(peer, Pkt *, 0);
 	peer->commit_jsoncmd = NULL;
 	list_head_init(&peer->outgoing_txs);
+	list_head_init(&peer->pay_commands);
 	peer->close_watch_timeout = NULL;
 	peer->anchor.watches = NULL;
 	peer->cur_commit.watch = NULL;
@@ -1110,13 +1112,6 @@ const struct json_command connect_command = {
 	"Returns an empty result on success"
 };
 
-static void complete_pay_command(struct peer *peer,
-				 struct htlc *htlc,
-				 const struct rval *rval)
-{
-	/* FIXME: implement. */
-}
-
 /* FIXME: Keep a timeout for each peer, in case they're unresponsive. */
 
 /* FIXME: Make sure no HTLCs in any unrevoked commit tx are live. */
@@ -2325,6 +2320,9 @@ static void route_htlc_onwards(struct peer *peer,
 	struct pubkey id;
 	struct peer *next;
 
+	log_debug_struct(peer->log, "Forwarding HTLC %s", struct sha256, &htlc->rhash);
+	log_add(peer->log, " (id %"PRIu64")", htlc->id);
+	
 	if (!proto_to_pubkey(peer->dstate->secpctx, pb_id, &id)) {
 		log_unusual(peer->log,
 			    "Malformed pubkey for HTLC %"PRIu64, htlc->id);
@@ -2334,8 +2332,9 @@ static void route_htlc_onwards(struct peer *peer,
 
 	next = find_peer(peer->dstate, &id);
 	if (!next || !next->nc) {
-		log_unusual(peer->log, "Can't route HTLC %"PRIu64, htlc->id);
-		log_add_struct(peer->log, " no peer %s", struct pubkey, &id);
+		log_unusual(peer->log, "Can't route HTLC %"PRIu64": no %speer ",
+			    htlc->id, next ? "ready " : "");
+		log_add_struct(peer->log, "%s", struct pubkey, &id);
 		if (!peer->dstate->dev_never_routefail)
 			command_htlc_fail(peer, htlc);
 		return;
@@ -2352,6 +2351,8 @@ static void route_htlc_onwards(struct peer *peer,
 		return;
 	}
 
+	log_debug_struct(peer->log, "HTLC forward to %s", struct pubkey, &next->id);
+
 	/* This checks the HTLC itself is possible. */
 	if (!command_htlc_add(next, msatoshis,
 			      abs_locktime_to_blocks(&htlc->expiry)

daemon/peer.h

@@ -127,6 +127,9 @@ struct peer {
 	/* 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;
 
@@ -258,6 +261,12 @@ struct htlc *peer_new_htlc(struct peer *peer,
 			   struct htlc *src,
 			   enum channel_side side);
 
+struct htlc *command_htlc_add(struct peer *peer, u64 msatoshis,
+			      unsigned int expiry,
+			      const struct sha256 *rhash,
+			      struct htlc *src,
+			      const u8 *route);
+
 /* Peer has recieved revocation. */
 void peer_update_complete(struct peer *peer);
 

daemon/test/test.sh

@@ -9,6 +9,7 @@ scripts/setup.sh
 
 DIR1=/tmp/lightning.$$.1
 DIR2=/tmp/lightning.$$.2
+DIR3=/tmp/lightning.$$.3
 
 REDIR1="$DIR1/output"
 REDIR2="$DIR2/output"
@@ -81,6 +82,7 @@ done
 
 LCLI1="../lightning-cli --lightning-dir=$DIR1"
 LCLI2="../lightning-cli --lightning-dir=$DIR2"
+LCLI3="../lightning-cli --lightning-dir=$DIR3"
 
 if [ -n "$VERBOSE" ]; then
     FGREP="fgrep"
@@ -105,6 +107,14 @@ lcli2()
     $LCLI2 "$@"
 }
 
+lcli3()
+{
+    if [ -n "$VERBOSE" ]; then
+	echo $LCLI3 "$@" >&2
+    fi
+    $LCLI3 "$@"
+}
+
 blockheight()
 {
     $CLI getblockcount
@@ -217,9 +227,10 @@ all_ok()
     # Look for valgrind errors.
     if grep ^== $DIR1/errors; then exit 1; fi
     if grep ^== $DIR2/errors; then exit 1; fi
+    if grep ^== $DIR3/errors; then exit 1; fi
     scripts/shutdown.sh
 
-    trap "rm -rf $DIR1 $DIR2" EXIT
+    trap "rm -rf $DIR1 $DIR2 $DIR3" EXIT
     exit 0
 }
 
@@ -228,7 +239,7 @@ if [ -n "$CRASH_ON_FAIL" ]; then
 else
     trap "echo Results in $DIR1 and $DIR2 >&2; cat $DIR1/errors $DIR2/errors >&2" EXIT
 fi
-mkdir $DIR1 $DIR2
+mkdir $DIR1 $DIR2 $DIR3
 
 if [ -n "$MANUALCOMMIT" ]; then
     # Aka. never. 
@@ -255,6 +266,8 @@ locktime-blocks=6
 commit-time=$COMMIT_TIME
 EOF
 
+cp $DIR2/config $DIR3/config
+
 if [ -n "$DIFFERENT_FEES" ]; then
     FEE_RATE2=300000
     CLOSE_FEE_RATE2=30000
@@ -275,6 +288,7 @@ if [ -n "$GDB2" ]; then
 else
     $PREFIX ../lightningd --lightning-dir=$DIR2 > $REDIR2 2> $REDIRERR2 &
 fi
+$PREFIX ../lightningd --lightning-dir=$DIR3 > $DIR3/output 2> $DIR3/errors &
 
 if ! check "$LCLI1 getlog 2>/dev/null | $FGREP Hello"; then
     echo Failed to start daemon 1 >&2
@@ -286,10 +300,17 @@ if ! check "$LCLI2 getlog 2>/dev/null | $FGREP Hello"; then
     exit 1
 fi
 
+if ! check "$LCLI3 getlog 2>/dev/null | $FGREP Hello"; then
+    echo Failed to start daemon 3 >&2
+    exit 1
+fi
+
 ID1=`$LCLI1 getlog | sed -n 's/.*"ID: \([0-9a-f]*\)".*/\1/p'`
 ID2=`$LCLI2 getlog | sed -n 's/.*"ID: \([0-9a-f]*\)".*/\1/p'`
+ID3=`$LCLI3 getlog | sed -n 's/.*"ID: \([0-9a-f]*\)".*/\1/p'`
 
 PORT2=`$LCLI2 getlog | sed -n 's/.*on port \([0-9]*\).*/\1/p'`
+PORT3=`$LCLI3 getlog | sed -n 's/.*on port \([0-9]*\).*/\1/p'`
 
 # Make a payment into a P2SH for anchor.
 P2SHADDR=`$LCLI1 newaddr | sed -n 's/{ "address" : "\(.*\)" }/\1/p'`
@@ -767,6 +788,49 @@ lcli1 newhtlc $ID2 $(($HTLC_AMOUNT - 1)) $EXPIRY $RHASH4
 check lcli2 "getlog | $FGREP 'Short payment for HTLC'"
 check_status $A_AMOUNT $A_FEE "" $B_AMOUNT $B_FEE ""
 
+if [ ! -n "$MANUALCOMMIT" ]; then
+    # Test routing to a third node.
+    P2SHADDR2=`$LCLI2 newaddr | sed -n 's/{ "address" : "\(.*\)" }/\1/p'`
+    TXID2=`$CLI sendtoaddress $P2SHADDR2 0.01`
+    TX2=`$CLI getrawtransaction $TXID2`
+    $CLI generate 1
+
+    lcli2 connect localhost $PORT3 $TX2
+    check_tx_spend lcli2
+    $CLI generate 3
+
+    # Make sure it's STATE_NORMAL.
+    check_peerstate lcli3 STATE_NORMAL
+
+    # More than enough to cover commit fees.
+    HTLC_AMOUNT=100000000
+
+    # Tell node 1 about the 2->3 route.
+    lcli1 add-route $ID2 $ID3 546000 10 36 36
+    RHASH5=`lcli3 accept-payment $HTLC_AMOUNT | sed 's/.*"\([0-9a-f]*\)".*/\1/'`
+
+    # Try wrong hash.
+    if lcli1 pay $ID3 $HTLC_AMOUNT $RHASH4; then
+	echo Paid with wrong hash? >&2
+	exit 1
+    fi
+
+    # Try underpaying.
+    if lcli1 pay $ID3 $(($HTLC_AMOUNT-1)) $RHASH5; then
+	echo Paid with too little? >&2
+	exit 1
+    fi
+
+    # Pay correctly.
+    lcli1 pay $ID3 $HTLC_AMOUNT $RHASH5
+
+    # Node 3 should end up with that amount (minus 1/2 tx fee)
+    # Note that it is delayed a little, since node2 fulfils as soon as fulfill
+    # starts.
+    check lcli3 "getpeers | $FGREP \"\\\"our_amount\\\" : $(($HTLC_AMOUNT - $NO_HTLCS_FEE / 2))\""
+    lcli3 close $ID2
+fi
+
 lcli1 close $ID2
 
 # They should be negotiating the close.