channeld: use fulfilled_htlc and failed_htlc msgs in single htlc case.

We use these for receiving arrays at init time, we should also use them
for fulfull/fail of HTLCs in normal operation.  That we we benefit from all
those assertions.

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

channeld/channel.c

@@ -2195,16 +2195,19 @@ static void handle_feerates(struct peer *peer, const u8 *inmsg)
 
 static void handle_preimage(struct peer *peer, const u8 *inmsg)
 {
-	u64 id;
-	struct preimage preimage;
+	struct fulfilled_htlc fulfilled_htlc;
 	struct htlc *h;
 
-	if (!fromwire_channel_fulfill_htlc(inmsg, &id, &preimage))
+	if (!fromwire_channel_fulfill_htlc(inmsg, &fulfilled_htlc))
 		master_badmsg(WIRE_CHANNEL_FULFILL_HTLC, inmsg);
 
-	switch (channel_fulfill_htlc(peer->channel, REMOTE, id, &preimage, &h)) {
+	switch (channel_fulfill_htlc(peer->channel, REMOTE,
+				     fulfilled_htlc.id,
+				     &fulfilled_htlc.payment_preimage,
+				     &h)) {
 	case CHANNEL_ERR_REMOVE_OK:
-		h->r = tal_dup(h, struct preimage, &preimage);
+		h->r = tal_dup(h, struct preimage,
+			       &fulfilled_htlc.payment_preimage);
 		send_fail_or_fulfill(peer, h);
 		start_commit_timer(peer);
 		return;
@@ -2217,39 +2220,27 @@ static void handle_preimage(struct peer *peer, const u8 *inmsg)
 	case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
 	case CHANNEL_ERR_BAD_PREIMAGE:
 		status_failed(STATUS_FAIL_MASTER_IO,
-			      "HTLC %"PRIu64" preimage failed", id);
+			      "HTLC %"PRIu64" preimage failed",
+			      fulfilled_htlc.id);
 	}
 	abort();
 }
 
 static void handle_fail(struct peer *peer, const u8 *inmsg)
 {
-	u64 id;
-	u8 *errpkt;
-	u16 failcode;
-	struct short_channel_id scid;
+	struct failed_htlc *failed_htlc;
 	enum channel_remove_err e;
 	struct htlc *h;
 
-	if (!fromwire_channel_fail_htlc(inmsg, inmsg, &id, &errpkt,
-					&failcode, &scid))
+	if (!fromwire_channel_fail_htlc(inmsg, inmsg, &failed_htlc))
 		master_badmsg(WIRE_CHANNEL_FAIL_HTLC, inmsg);
 
-	if (failcode && tal_len(errpkt))
-		status_failed(STATUS_FAIL_MASTER_IO,
-			      "Invalid channel_fail_htlc: %s with errpkt?",
-			      onion_type_name(failcode));
-
-	e = channel_fail_htlc(peer->channel, REMOTE, id, &h);
+	e = channel_fail_htlc(peer->channel, REMOTE, failed_htlc->id, &h);
 	switch (e) {
 	case CHANNEL_ERR_REMOVE_OK:
-		h->failcode = failcode;
-		h->fail = tal_steal(h, errpkt);
-		if (failcode & UPDATE)
-			h->failed_scid
-				= tal_dup(h, struct short_channel_id, &scid);
-		else
-			h->failed_scid = NULL;
+		h->failcode = failed_htlc->failcode;
+		h->fail = tal_steal(h, failed_htlc->failreason);
+		h->failed_scid = tal_steal(h, failed_htlc->scid);
 		send_fail_or_fulfill(peer, h);
 		start_commit_timer(peer);
 		return;
@@ -2259,7 +2250,8 @@ static void handle_fail(struct peer *peer, const u8 *inmsg)
 	case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
 	case CHANNEL_ERR_BAD_PREIMAGE:
 		status_failed(STATUS_FAIL_MASTER_IO,
-			      "HTLC %"PRIu64" removal failed: %s", id,
+			      "HTLC %"PRIu64" removal failed: %s",
+			      failed_htlc->id,
 			      channel_remove_err_name(e));
 	}
 	abort();

channeld/channel_wire.csv

@@ -82,19 +82,11 @@ channel_offer_htlc_reply,,failurestr,failurestrlen*u8
 # Main daemon found out the preimage for an HTLC
 #include <bitcoin/preimage.h>
 channel_fulfill_htlc,1005
-channel_fulfill_htlc,,id,u64
-channel_fulfill_htlc,,payment_preimage,struct preimage
+channel_fulfill_htlc,,fulfilled_htlc,struct fulfilled_htlc
 
 # Main daemon says HTLC failed
 channel_fail_htlc,1006
-channel_fail_htlc,,id,u64
-# If this is non-zero length, you need to wrap this and pass it on.
-channel_fail_htlc,,len,u16
-channel_fail_htlc,,error_pkt,len*u8
-# If it errcode is != 0, it's a local error, otherwise we're passing through.
-channel_fail_htlc,,errcode,u16
-# If errcode & UPDATE, this says which outgoing channel failed.
-channel_fail_htlc,,which_channel,struct short_channel_id
+channel_fail_htlc,,failed_htlc,struct failed_htlc
 
 # When we receive funding_locked.
 channel_got_funding_locked,1019

lightningd/peer_htlcs.c

@@ -1,5 +1,6 @@
 #include <bitcoin/tx.h>
 #include <ccan/build_assert/build_assert.h>
+#include <ccan/cast/cast.h>
 #include <ccan/crypto/ripemd160/ripemd160.h>
 #include <ccan/mem/mem.h>
 #include <ccan/tal/str/str.h>
@@ -88,6 +89,7 @@ static void fail_in_htlc(struct htlc_in *hin,
 			 const u8 *failuremsg,
 			 const struct short_channel_id *out_channelid)
 {
+	struct failed_htlc failed_htlc;
 	assert(!hin->preimage);
 
 	assert(failcode || failuremsg);
@@ -112,12 +114,15 @@ static void fail_in_htlc(struct htlc_in *hin,
 	if (channel_on_chain(hin->key.channel))
 		return;
 
+	failed_htlc.id = hin->key.id;
+	failed_htlc.failcode = hin->failcode;
+	failed_htlc.failreason = cast_const(u8 *, hin->failuremsg);
+	if (failed_htlc.failcode & UPDATE)
+		failed_htlc.scid = &hin->failoutchannel;
+	else
+		failed_htlc.scid = NULL;
 	subd_send_msg(hin->key.channel->owner,
-		      take(towire_channel_fail_htlc(hin,
-						    hin->key.id,
-						    hin->failuremsg,
-						    hin->failcode,
-						    &hin->failoutchannel)));
+		      take(towire_channel_fail_htlc(NULL, &failed_htlc)));
 }
 
 /* This is used for cases where we can immediately fail the HTLC. */
@@ -228,7 +233,10 @@ static void fulfill_htlc(struct htlc_in *hin, const struct preimage *preimage)
 	if (channel_on_chain(channel)) {
 		msg = towire_onchain_known_preimage(hin, preimage);
 	} else {
-		msg = towire_channel_fulfill_htlc(hin, hin->key.id, preimage);
+		struct fulfilled_htlc fulfilled_htlc;
+		fulfilled_htlc.id = hin->key.id;
+		fulfilled_htlc.payment_preimage = *preimage;
+		msg = towire_channel_fulfill_htlc(hin, &fulfilled_htlc);
 	}
 	subd_send_msg(channel->owner, take(msg));
 }