lightnind: _ dev-disconnect argument to suppress commit timer.

Required for catching daemon in exact state.

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

channeld/channel.c

@@ -20,6 +20,7 @@
 #include <common/daemon_conn.h>
 #include <common/debug.h>
 #include <common/derive_basepoints.h>
+#include <common/dev_disconnect.h>
 #include <common/htlc_tx.h>
 #include <common/key_derive.h>
 #include <common/msg_queue.h>
@@ -618,6 +619,13 @@ static void send_commit(struct peer *peer)
 	u8 *msg;
 	const struct htlc **changed_htlcs;
 
+	/* Hack to suppress all commit sends if dev_disconnect says to */
+	if (dev_suppress_commit) {
+		peer->commit_timer = NULL;
+		tal_free(tmpctx);
+		return;
+	}
+
 	/* FIXME: Document this requirement in BOLT 2! */
 	/* We can't send two commits in a row. */
 	if (channel_awaiting_revoke_and_ack(peer->channel)) {

common/crypto_sync.c

@@ -28,7 +28,8 @@ bool sync_crypto_write(struct crypto_state *cs, int fd, const void *msg TAKES)
 	case DEV_DISCONNECT_BLACKHOLE:
 		dev_blackhole_fd(fd);
 		break;
-	default:
+	case DEV_DISCONNECT_SUPPRESS_COMMIT:
+	case DEV_DISCONNECT_NORMAL:
 		break;
 	}
 	ret = write_all(fd, enc, tal_len(enc));

common/cryptomsg.c

@@ -355,7 +355,8 @@ struct io_plan *peer_write_message(struct io_conn *conn,
 	case DEV_DISCONNECT_BLACKHOLE:
 		dev_blackhole_fd(io_conn_fd(conn));
 		break;
-	default:
+	case DEV_DISCONNECT_SUPPRESS_COMMIT:
+	case DEV_DISCONNECT_NORMAL:
 		break;
 	}
 

common/dev_disconnect.c

@@ -16,6 +16,8 @@ static int dev_disconnect_fd = -1;
 static char dev_disconnect_line[200];
 static int dev_disconnect_count, dev_disconnect_len;
 
+bool dev_suppress_commit;
+
 void dev_disconnect_init(int fd)
 {
 	int r;
@@ -44,7 +46,7 @@ void dev_disconnect_init(int fd)
 	dev_disconnect_fd = fd;
 }
 
-char dev_disconnect(int pkt_type)
+enum dev_disconnect dev_disconnect(int pkt_type)
 {
 	if (!streq(wire_type_name(pkt_type), dev_disconnect_line+1))
 		return DEV_DISCONNECT_NORMAL;
@@ -58,6 +60,9 @@ char dev_disconnect(int pkt_type)
 	lseek(dev_disconnect_fd, dev_disconnect_len+1, SEEK_CUR);
 
 	status_trace("dev_disconnect: %s", dev_disconnect_line);
+
+	if (dev_disconnect_line[0] == DEV_DISCONNECT_SUPPRESS_COMMIT)
+		dev_suppress_commit = true;
 	return dev_disconnect_line[0];
 }
 

common/dev_disconnect.h

@@ -3,14 +3,23 @@
 #include "config.h"
 #include <stdbool.h>
 
-#define DEV_DISCONNECT_BEFORE '-'
-#define DEV_DISCONNECT_AFTER '+'
-#define DEV_DISCONNECT_DROPPKT '@'
-#define DEV_DISCONNECT_BLACKHOLE '0'
-#define DEV_DISCONNECT_NORMAL 0
+enum dev_disconnect {
+	/* Do nothing. */
+	DEV_DISCONNECT_NORMAL = 0,
+	/* Close connection before sending packet (and fail write). */
+	DEV_DISCONNECT_BEFORE = '-',
+	/* Close connection after sending packet. */
+	DEV_DISCONNECT_AFTER = '+',
+	/* Close connection after dropping packet. */
+	DEV_DISCONNECT_DROPPKT = '@',
+	/* Swallow all writes from now on, and do no more reads. */
+	DEV_DISCONNECT_BLACKHOLE = '0',
+	/* Disable commit timer after sending this. */
+	DEV_DISCONNECT_SUPPRESS_COMMIT = '_'
+};
 
 /* Force a close fd before or after a certain packet type */
-char dev_disconnect(int pkt_type);
+enum dev_disconnect dev_disconnect(int pkt_type);
 
 /* Make next write on fd fail as if they'd disconnected. */
 void dev_sabotage_fd(int fd);
@@ -21,4 +30,7 @@ void dev_blackhole_fd(int fd);
 /* For debug code to set in daemon. */
 void dev_disconnect_init(int fd);
 
+/* Hack for channeld to do DEV_DISCONNECT_SUPPRESS_COMMIT. */
+extern bool dev_suppress_commit;
+
 #endif /* LIGHTNING_COMMON_DEV_DISCONNECT_H */

lightningd/peer_control.c

@@ -253,7 +253,7 @@ static void peer_start_closingd(struct peer *peer,
 				bool reconnected);
 
 /* FIXME: Fake NOP dev_disconnect/dev_sabotage_fd for below. */
-char dev_disconnect(int pkt_type)
+enum dev_disconnect dev_disconnect(int pkt_type)
 {
 	return DEV_DISCONNECT_NORMAL;
 }

lightningd/test/run-cryptomsg.c

@@ -48,7 +48,7 @@ void dev_sabotage_fd(int fd UNNEEDED)
 { fprintf(stderr, "dev_sabotage_fd called!\n"); abort(); }
 /* AUTOGENERATED MOCKS END */
 
-char dev_disconnect(int pkt_type)
+enum dev_disconnect dev_disconnect(int pkt_type)
 {
 	return DEV_DISCONNECT_NORMAL;
 }