protocol: add close fee logic.

The closer proposes the fee.  This is simple, at least.

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

lightning.pb-c.c

@@ -1399,7 +1399,7 @@ const ProtobufCMessageDescriptor update_complete__descriptor =
   (ProtobufCMessageInit) update_complete__init,
   NULL,NULL,NULL    /* reserved[123] */
 };
-static const ProtobufCFieldDescriptor close_channel__field_descriptors[1] =
+static const ProtobufCFieldDescriptor close_channel__field_descriptors[2] =
 {
   {
     "sig",
@@ -1413,14 +1413,27 @@ static const ProtobufCFieldDescriptor close_channel__field_descriptors[1] =
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
   },
+  {
+    "close_fee",
+    2,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_UINT64,
+    0,   /* quantifier_offset */
+    offsetof(CloseChannel, close_fee),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
 };
 static const unsigned close_channel__field_indices_by_name[] = {
+  1,   /* field[1] = close_fee */
   0,   /* field[0] = sig */
 };
 static const ProtobufCIntRange close_channel__number_ranges[1 + 1] =
 {
   { 1, 0 },
-  { 0, 1 }
+  { 0, 2 }
 };
 const ProtobufCMessageDescriptor close_channel__descriptor =
 {
@@ -1430,7 +1443,7 @@ const ProtobufCMessageDescriptor close_channel__descriptor =
   "CloseChannel",
   "",
   sizeof(CloseChannel),
-  1,
+  2,
   close_channel__field_descriptors,
   close_channel__field_indices_by_name,
   1,  close_channel__number_ranges,

lightning.pb-c.h

@@ -293,10 +293,14 @@ struct  _CloseChannel
    * as per the last commit tx.
    */
   Signature *sig;
+  /*
+   * Fee to pay for close transaction.
+   */
+  uint64_t close_fee;
 };
 #define CLOSE_CHANNEL__INIT \
  { PROTOBUF_C_MESSAGE_INIT (&close_channel__descriptor) \
-    , NULL }
+    , NULL, 0 }
 
 
 /*

lightning.proto

@@ -125,6 +125,8 @@ message close_channel {
   // output to my open->final and your open->final,
   // as per the last commit tx.
   required signature sig = 1;
+  // Fee to pay for close transaction.
+  required uint64 close_fee = 2;
 }
 
 // OK, here's my sig so you can broadcast it too.  We're done.

pkt.c

@@ -110,9 +110,12 @@ struct pkt *open_commit_sig_pkt(const tal_t *ctx, const struct signature *sig)
 	return to_pkt(ctx, PKT__PKT_OPEN_COMMIT_SIG, &o);
 }
 
-struct pkt *close_channel_pkt(const tal_t *ctx, const struct signature *sig)
+struct pkt *close_channel_pkt(const tal_t *ctx,
+			      uint64_t fee,
+			      const struct signature *sig)
 {
 	CloseChannel c = CLOSE_CHANNEL__INIT;
+	c.close_fee = fee;
 	c.sig = signature_to_proto(ctx, sig);
 	return to_pkt(ctx, PKT__PKT_CLOSE, &c);
 }

pkt.h

@@ -65,9 +65,12 @@ struct pkt *open_commit_sig_pkt(const tal_t *ctx, const struct signature *sig);
 /**
  * close_channel_pkt - create an close_channel message
  * @ctx: tal context to allocate off.
+ * @fee: the fee for the transaction.
  * @sig: the signature for the close transaction input.
  */
-struct pkt *close_channel_pkt(const tal_t *ctx, const struct signature *sig);
+struct pkt *close_channel_pkt(const tal_t *ctx,
+			      uint64_t fee,
+			      const struct signature *sig);
 
 /**
  * close_channel_complete_pkt - create an close_channel_complete message

test-cli/close-channel.c

@@ -18,6 +18,7 @@
 #include "find_p2sh_out.h"
 #include "protobuf_convert.h"
 #include "gather_updates.h"
+#include "opt_bits.h"
 #include <unistd.h>
 
 int main(int argc, char *argv[])
@@ -29,19 +30,25 @@ int main(int argc, char *argv[])
 	struct pkt *pkt;
 	struct signature sig;
 	struct privkey privkey;
-	bool testnet, complete = false;
+	bool testnet;
 	struct pubkey pubkey1, pubkey2;
 	u8 *redeemscript;
 	uint64_t our_amount, their_amount;
+	char *close_file = NULL;
+	u64 close_fee = 10000;
 
 	err_set_progname(argv[0]);
 
-	opt_register_noarg("--complete", opt_set_bool, &complete,
-			   "Create a close_transaction_complete msg instead");
+	opt_register_arg("--complete=<close-msg-file>",
+			 opt_set_charp, NULL, &close_file,
+			 "Create a close_transaction_complete msg instead");
 	opt_register_noarg("--help|-h", opt_usage_and_exit,
 			   "<open-channel-file1> <open-channel-file2> <anchor-file> <commit-privkey> [{+/-}update-protobuf]...\n"
 			   "Create the signature needed for the close transaction",
 			   "Print this message.");
+	opt_register_arg("--close-fee=<bits>",
+			 opt_set_bits, opt_show_bits, &close_fee,
+			 "100's of satoshi to pay for close tx");
 
  	opt_parse(&argc, argv, opt_log_stderr_exit);
 
@@ -57,7 +64,14 @@ int main(int argc, char *argv[])
 	if (!testnet)
 		errx(1, "Private key '%s' not on testnet!", argv[4]);
 
-	gather_updates(o1, o2, a, 0, argv + 5, &our_amount, &their_amount,
+	if (close_file) {
+		CloseChannel *c;
+		c = pkt_from_file(close_file, PKT__PKT_CLOSE)->close;
+		close_fee = c->close_fee;
+	}
+	
+	gather_updates(o1, o2, a, close_fee, argv + 5,
+		       &our_amount, &their_amount,
 		       NULL, NULL, NULL);
 
 	/* Get pubkeys */
@@ -72,17 +86,16 @@ int main(int argc, char *argv[])
 	/* This is what the anchor pays to. */
 	redeemscript = bitcoin_redeem_2of2(ctx, &pubkey1, &pubkey2);
 
-	/* FIXME: Add fee! */
 	close_tx = create_close_tx(ctx, o1, o2, a, our_amount, their_amount);
 
 	/* Sign it for them. */
 	sign_tx_input(ctx, close_tx, 0, redeemscript, tal_count(redeemscript),
 		      &privkey, &pubkey1, &sig);
 
-	if (complete)
+	if (close_file)
 		pkt = close_channel_complete_pkt(ctx, &sig);
 	else
-		pkt = close_channel_pkt(ctx, &sig);
+		pkt = close_channel_pkt(ctx, close_fee, &sig);
 	if (!write_all(STDOUT_FILENO, pkt, pkt_totlen(pkt)))
 		err(1, "Writing out packet");
 

test-cli/create-close-tx.c

@@ -56,7 +56,8 @@ int main(int argc, char *argv[])
 		errx(1, "Invalid o2 commit_key");
 	
 	/* Get delta by accumulting all the updates. */
-	gather_updates(o1, o2, a, 0, argv + 6, &our_amount, &their_amount,
+	gather_updates(o1, o2, a, close->close_fee, argv + 6,
+		       &our_amount, &their_amount,
 		       NULL, NULL, NULL);
 
 	/* This is what the anchor pays to; figure out which output. */

test-cli/scripts/test.sh

@@ -176,7 +176,7 @@ fi
 
 # Now close channel by mutual consent.
 $PREFIX ./close-channel A-open.pb B-open.pb A-anchor.pb $A_TMPKEY $A_UPDATE_PKTS > A-close.pb
-$PREFIX ./close-channel --complete B-open.pb A-open.pb A-anchor.pb $B_TMPKEY $B_UPDATE_PKTS > B-close-complete.pb
+$PREFIX ./close-channel --complete=A-close.pb B-open.pb A-open.pb A-anchor.pb $B_TMPKEY $B_UPDATE_PKTS > B-close-complete.pb
 $PREFIX ./create-close-tx A-open.pb B-open.pb A-anchor.pb A-close.pb B-close-complete.pb $A_UPDATE_PKTS > A-close.tx
 
 $CLI sendrawtransaction `cut -d: -f1 A-close.tx` > close.txid