lightningd/status: support daemon_conn for status_trace and status_failed.

We remove the unused status_send_fd, and rename status_send_sync (it
should only be used for that case now).

We add a status_setup_async(), and wire things internally to use that
if it's set up: status_setup() is renamed status_setup_sync().

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

lightningd/channel/channel.c

@@ -312,7 +312,7 @@ int main(int argc, char *argv[])
 	daemon_conn_init(peer, &peer->master, REQ_FD, req_in);
 	peer->channel = NULL;
 
-	status_setup(REQ_FD);
+	status_setup_async(&peer->master);
 	msg_queue_init(&peer->peer_out, peer);
 
 	daemon_conn_init(peer, &peer->gossip_client, GOSSIP_FD,

lightningd/connection.c

@@ -1,7 +1,9 @@
 #include "connection.h"
+#include <ccan/fdpass/fdpass.h>
 #include <ccan/io/fdpass/fdpass.h>
 #include <ccan/take/take.h>
 #include <wire/wire_io.h>
+#include <wire/wire_sync.h>
 
 struct io_plan *daemon_conn_read_next(struct io_conn *conn,
 				      struct daemon_conn *dc)
@@ -30,6 +32,26 @@ struct io_plan *daemon_conn_write_next(struct io_conn *conn,
 	}
 }
 
+bool daemon_conn_sync_flush(struct daemon_conn *dc)
+{
+	const u8 *msg;
+
+	/* Flush any current packet. */
+	if (!io_flush_sync(dc->conn))
+		return false;
+
+	/* Flush existing messages. */
+	while ((msg = msg_dequeue(&dc->out)) != NULL) {
+		int fd = msg_is_fd(msg);
+		if (fd >= 0) {
+			if (!fdpass_send(io_conn_fd(dc->conn), fd))
+				return false;
+		} else if (!wire_sync_write(io_conn_fd(dc->conn), msg))
+			return false;
+	}
+	return true;
+}
+
 static struct io_plan *daemon_conn_start(struct io_conn *conn,
 					 struct daemon_conn *dc)
 {

lightningd/connection.h

@@ -66,4 +66,8 @@ struct io_plan *daemon_conn_write_next(struct io_conn *conn,
 struct io_plan *daemon_conn_read_next(struct io_conn *conn,
 				      struct daemon_conn *dc);
 
+/**
+ * daemon_conn_sync_flush - Flush connection by sending all messages now..
+ */
+bool daemon_conn_sync_flush(struct daemon_conn *dc);
 #endif /* LIGHTNING_LIGHTNINGD_CONNECTION_H */

lightningd/gossip/gossip.c

@@ -537,8 +537,8 @@ int main(int argc, char *argv[])
 	timers_init(&daemon->timers, time_mono());
 
 	/* stdin == control */
-	status_setup(STDIN_FILENO);
 	daemon_conn_init(daemon, &daemon->master, STDIN_FILENO, recv_req);
+	status_setup_async(&daemon->master);
 	for (;;) {
 		struct timer *expired = NULL;
 		io_loop(&daemon->timers, &expired);

lightningd/handshake/handshake.c

@@ -308,7 +308,7 @@ static void act_one_initiator(struct handshake *h, int fd,
 	struct act_one act1;
 	size_t len;
 
-	status_send(towire_initr_act_one(h));
+	status_send_sync(towire_initr_act_one(h));
 
 	/* BOLT #8:
 	 *
@@ -390,7 +390,7 @@ static void act_one_responder(struct handshake *h, int fd, struct pubkey *re)
 {
 	struct act_one act1;
 
-	status_send(towire_respr_act_one(h));
+	status_send_sync(towire_respr_act_one(h));
 
 	/* BOLT #8:
 	 *
@@ -519,7 +519,7 @@ static void act_two_responder(struct handshake *h, int fd,
 	struct act_two act2;
 	size_t len;
 
-	status_send(towire_respr_act_two(h));
+	status_send_sync(towire_respr_act_two(h));
 
 	/* BOLT #8:
 	 *
@@ -602,7 +602,7 @@ static void act_two_initiator(struct handshake *h, int fd, struct pubkey *re)
 {
 	struct act_two act2;
 
-	status_send(towire_initr_act_two(h));
+	status_send_sync(towire_initr_act_two(h));
 
 	/* BOLT #8:
 	 *
@@ -731,7 +731,7 @@ static void act_three_initiator(struct handshake *h, int fd,
 	u8 spub[PUBKEY_DER_LEN];
 	size_t len = sizeof(spub);
 
-	status_send(towire_initr_act_three(h));
+	status_send_sync(towire_initr_act_three(h));
 
 	/* BOLT #8:
 	 *   * `c = encryptWithAD(temp_k2, 1, h, s.pub.serializeCompressed())`
@@ -803,7 +803,7 @@ static void act_three_responder(struct handshake *h, int fd,
 	struct act_three act3;
 	u8 der[PUBKEY_DER_LEN];
 
-	status_send(towire_respr_act_three(h));
+	status_send_sync(towire_respr_act_three(h));
 
 	/* BOLT #8:
 	 *
@@ -979,7 +979,7 @@ int main(int argc, char *argv[])
 	subdaemon_debug(argc, argv);
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
-	status_setup(REQ_FD);
+	status_setup_sync(REQ_FD);
 
 	hsm_setup(hsmfd);
 

lightningd/handshake/test/run-handshake.c

@@ -25,7 +25,7 @@ static ssize_t fake_write_all(int fd, const void *buf, size_t count)
 static const char *status_prefix;
 
 /* Simply print out status updates. */
-#define status_send(msg)			\
+#define status_send_sync(msg)			\
 	printf("%s:# Act %s\n", status_prefix,	\
 	       fromwire_peektype(msg) == WIRE_INITR_ACT_ONE ? "One"	\
 	       : fromwire_peektype(msg) == WIRE_INITR_ACT_TWO ? "Two"	\

lightningd/hsm/hsm.c

@@ -426,7 +426,7 @@ int main(int argc, char *argv[])
 
 	master = tal(NULL, struct daemon_conn);
 	daemon_conn_init(master, master, STDIN_FILENO, control_received_req);
-	status_setup(STDIN_FILENO);
+	status_setup_async(master);
 
 	/* When conn closes, everything is freed. */
 	tal_steal(master->conn, master);

lightningd/opening/opening.c

@@ -676,7 +676,7 @@ int main(int argc, char *argv[])
 	signal(SIGCHLD, SIG_IGN);
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
-	status_setup(REQ_FD);
+	status_setup_sync(REQ_FD);
 
 	msg = wire_sync_read(state, REQ_FD);
 	if (!msg)

lightningd/status.c

@@ -1,4 +1,3 @@
-#include "status.h"
 #include "utils.h"
 #include "wire/wire.h"
 #include "wire/wire_sync.h"
@@ -8,18 +7,32 @@
 #include <ccan/err/err.h>
 #include <ccan/fdpass/fdpass.h>
 #include <ccan/read_write_all/read_write_all.h>
+#include <ccan/take/take.h>
 #include <ccan/tal/str/str.h>
+#include <lightningd/connection.h>
+#include <lightningd/status.h>
 #include <stdarg.h>
 
 static int status_fd = -1;
+static struct daemon_conn *status_conn;
 const void *trc;
 
-void status_setup(int fd)
+void status_setup_sync(int fd)
 {
+	assert(status_fd == -1);
+	assert(!status_conn);
 	status_fd = fd;
 	trc = tal_tmpctx(NULL);
 }
 
+void status_setup_async(struct daemon_conn *master)
+{
+	assert(status_fd == -1);
+	assert(!status_conn);
+	status_conn = master;
+	trc = tal_tmpctx(NULL);
+}
+
 static bool too_large(size_t len, int type)
 {
 	if (len > 65535) {
@@ -30,7 +43,7 @@ static bool too_large(size_t len, int type)
 	return false;
 }
 
-void status_send(const u8 *p)
+void status_send_sync(const u8 *p)
 {
 	const u8 *msg = p;
 	assert(status_fd >= 0);
@@ -43,16 +56,6 @@ void status_send(const u8 *p)
 	tal_free(p);
 }
 
-void status_send_fd(int fd)
-{
-	assert(status_fd >= 0);
-	assert(fd >= 0);
-
-	if (!fdpass_send(status_fd, fd))
-		err(1, "Writing out status fd %i", fd);
-	close(fd);
-}
-
 static void status_send_with_hdr(u16 type, const void *p, size_t len)
 {
 	be16 be_type, be_len;
@@ -62,13 +65,19 @@ static void status_send_with_hdr(u16 type, const void *p, size_t len)
 
 	be_type = cpu_to_be16(type);
 	be_len = cpu_to_be16(len + sizeof(be_type));
-	assert(status_fd >= 0);
 	assert(be16_to_cpu(be_len) == len + sizeof(be_type));
 
-	if (!write_all(status_fd, &be_len, sizeof(be_len))
-	    || !write_all(status_fd, &be_type, sizeof(be_type))
-	    || !write_all(status_fd, p, len))
-		err(1, "Writing out status %u len %zu", type, len);
+	if (status_fd >= 0) {
+		if (!write_all(status_fd, &be_len, sizeof(be_len))
+		    || !write_all(status_fd, &be_type, sizeof(be_type))
+		    || !write_all(status_fd, p, len))
+			err(1, "Writing out status %u len %zu", type, len);
+	} else {
+		u8 *msg = tal_arr(NULL, u8, sizeof(be_type) + len);
+		memcpy(msg, &be_type, sizeof(be_type));
+		memcpy(msg + sizeof(be_type), p, len);
+		daemon_conn_send(status_conn, take(msg));
+	}
 }
 
 void status_trace(const char *fmt, ...)
@@ -99,5 +108,10 @@ void status_failed(u16 code, const char *fmt, ...)
 	status_send_with_hdr(code, str, strlen(str));
 	va_end(ap);
 
+	/* Don't let it take forever. */
+	alarm(10);
+	if (status_conn)
+		daemon_conn_sync_flush(status_conn);
+
 	exit(0x80 | (code & 0xFF));
 }

lightningd/status.h

@@ -5,8 +5,11 @@
 #include <ccan/short_types/short_types.h>
 #include <stdlib.h>
 
+struct daemon_conn;
+
 /* Simple status reporting API. */
-void status_setup(int fd);
+void status_setup_sync(int fd);
+void status_setup_async(struct daemon_conn *master);
 
 /* Convenient context, frees up after every status_update/failed */
 extern const void *trc;
@@ -18,9 +21,7 @@ extern const void *trc;
 #define STATUS_FAIL 0x8000
 
 /* Send a message (frees the message). */
-void status_send(const u8 *msg);
-/* Send a file descriptor (closes fd). */
-void status_send_fd(int fd);
+void status_send_sync(const u8 *msg);
 /* Send a printf-style debugging trace. */
 void status_trace(const char *fmt, ...) PRINTF_FMT(1,2);
 /* Send a failure status code with printf-style msg, and exit. */