sync_crypto_write: support take(msg)

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

lightningd/crypto_sync.c

@@ -9,16 +9,14 @@
 #include <wire/wire.h>
 #include <wire/wire_sync.h>
 
-bool sync_crypto_write(struct crypto_state *cs, int fd, const void *msg)
+bool sync_crypto_write(struct crypto_state *cs, int fd, const void *msg TAKES)
 {
-	u8 *enc = cryptomsg_encrypt_msg(msg, cs, msg);
+	int type = fromwire_peektype(msg);
+	u8 *enc = cryptomsg_encrypt_msg(NULL, cs, msg);
 	bool ret;
 	bool post_sabotage = false;
 
-	status_trace("Writing crypto with sn=%"PRIu64" msg=%s",
-		     cs->sn-2, tal_hex(trc, msg));
-
-	switch (dev_disconnect(fromwire_peektype(msg))) {
+	switch (dev_disconnect(type)) {
 	case DEV_DISCONNECT_BEFORE:
 		dev_sabotage_fd(fd);
 		return false;

lightningd/crypto_sync.h

@@ -6,7 +6,7 @@
 
 struct crypto_state;
 
-bool sync_crypto_write(struct crypto_state *cs, int fd, const void *msg);
+bool sync_crypto_write(struct crypto_state *cs, int fd, const void *msg TAKES);
 u8 *sync_crypto_read(const tal_t *ctx, struct crypto_state *cs, int fd);
 
 #endif /* LIGHTNING_LIGHTNINGD_CRYPTO_SYNC_H */

lightningd/cryptomsg.c

@@ -236,7 +236,7 @@ static struct io_plan *peer_write_done(struct io_conn *conn,
 
 u8 *cryptomsg_encrypt_msg(const tal_t *ctx,
 			  struct crypto_state *cs,
-			  const u8 *msg)
+			  const u8 *msg TAKES)
 {
 	unsigned char npub[crypto_aead_chacha20poly1305_ietf_NPUBBYTES];
 	unsigned long long clen, mlen = tal_count(msg);
@@ -314,6 +314,8 @@ u8 *cryptomsg_encrypt_msg(const tal_t *ctx,
 
 	maybe_rotate_key(&cs->sn, &cs->sk, &cs->s_ck);
 
+	if (taken(msg))
+		tal_free(msg);
 	return out;
 }
 
@@ -336,8 +338,6 @@ struct io_plan *peer_write_message(struct io_conn *conn,
 	assert(!pcs->out);
 
 	pcs->out = cryptomsg_encrypt_msg(conn, &pcs->cs, msg);
-	if (taken(msg))
-		tal_free(msg);
 	pcs->next_out = next;
 
 	post = peer_write_done;

lightningd/opening/opening.c

@@ -181,10 +181,10 @@ static u8 *read_next_peer_msg(struct state *state, const tal_t *ctx)
 				return tal_free(msg);
 			}
 			if (pong && !sync_crypto_write(&state->cs, PEER_FD,
-						       pong))
-				peer_failed(PEER_FD, &state->cs, NULL, WIRE_OPENING_PEER_WRITE_FAILED,
+						       take(pong)))
+				peer_failed(PEER_FD, &state->cs, NULL,
+					    WIRE_OPENING_PEER_WRITE_FAILED,
 					    "Sending pong");
-			tal_free(pong);
 		} else if (is_gossip_msg(msg)) {
 			/* We relay gossip to gossipd, but don't relay from */
 			if (!wire_sync_write(GOSSIP_FD, take(msg)))
@@ -568,7 +568,7 @@ static u8 *fundee_channel(struct state *state,
 				    &ours->delayed_payment,
 				    &state->next_per_commit[LOCAL]);
 
-	if (!sync_crypto_write(&state->cs, PEER_FD, msg))
+	if (!sync_crypto_write(&state->cs, PEER_FD, take(msg)))
 		peer_failed(PEER_FD, &state->cs, NULL, WIRE_OPENING_PEER_WRITE_FAILED,
 			      "Writing accept_channel");
 

lightningd/peer_failed.c

@@ -36,7 +36,7 @@ void peer_failed(int peer_fd, struct crypto_state *cs,
 
 	/* This is only best-effort; don't block. */
 	fcntl(peer_fd, F_SETFL, fcntl(peer_fd, F_GETFL) | O_NONBLOCK);
-	sync_crypto_write(cs, peer_fd, msg);
+	sync_crypto_write(cs, peer_fd, take(msg));
 
 	status_failed(error_code, "%s", errmsg);
 }