From 5b2e829b4f582375198b2a0035fc16778adc149a Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Thu, 20 Sep 2018 14:01:27 +0930
Subject: [PATCH] hsmd: remove master pointer.

We used to use it to complain about bad requests, but we use the status conn
now, so it's unused except for tests and asserts.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 hsmd/hsmd.c | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/hsmd/hsmd.c b/hsmd/hsmd.c
index 402705227..d047e8e91 100644
--- a/hsmd/hsmd.c
+++ b/hsmd/hsmd.c
@@ -67,9 +67,6 @@ static struct {
 
 /*~ We keep track of clients, but there's not much to keep. */
 struct client {
-	/* The connection to lightningd itself */
-	struct client *master;
-
 	/* The ccan/io async io connection for this client: it closes, we die. */
 	struct io_conn *conn;
 
@@ -107,6 +104,12 @@ static size_t num_dbid_zero_clients;
 /*~ We need this deep inside bad_req_fmt, so we make it a global. */
 static struct daemon_conn *status_conn;
 
+/* This is used for various assertions and error cases. */
+static bool is_lightningd(const struct client *client)
+{
+	return client == dbid_zero_clients[0];
+}
+
 /*~ FIXME: This is used by debug.c.  Doesn't apply to us, but lets us link. */
 extern void dev_disconnect_init(int fd);
 void dev_disconnect_init(int fd UNUSED) { }
@@ -136,7 +139,7 @@ static PRINTF_FMT(4,5)
 
 	/*~ If the client was actually lightningd, it's Game Over; we actually
 	 * fail in this case, and it will too. */
-	if (c == c->master) {
+	if (is_lightningd(c)) {
 		status_broken("%s", str);
 		master_badmsg(fromwire_peektype(msg_in), msg_in);
 	}
@@ -184,13 +187,13 @@ static void destroy_client(struct client *c)
 			      "Failed to remove client dbid %"PRIu64, c->dbid);
 }
 
-static struct client *new_client(struct client *master,
+static struct client *new_client(const tal_t *ctx,
 				 const struct pubkey *id,
 				 u64 dbid,
 				 const u64 capabilities,
 				 int fd)
 {
-	struct client *c = tal(master, struct client);
+	struct client *c = tal(ctx, struct client);
 
 	/*~ All-zero pubkey is used for the initial master connection */
 	if (id) {
@@ -200,23 +203,22 @@ static struct client *new_client(struct client *master,
 	}
 	c->dbid = dbid;
 
-	c->master = master;
 	c->capabilities = capabilities;
 	/*~ This is the core of ccan/io: the connection creation calls a
 	 * callback which returns the initial plan to execute: in our case,
 	 * read a message.*/
-	c->conn = io_new_conn(master, fd, client_read_next, c);
+	c->conn = io_new_conn(ctx, fd, client_read_next, c);
 
 	/*~ tal_steal() moves a pointer to a new parent.  At this point, the
 	 * hierarchy is:
 	 *
-	 *   master -> c
-	 *   master -> c->conn
+	 *   ctx -> c
+	 *   ctx -> c->conn
 	 *
 	 * We want to the c->conn to own 'c', so that if the io_conn closes,
 	 * the client is freed:
 	 *
-	 *   master -> c->conn -> c.
+	 *   ctx -> c->conn -> c.
 	 */
 	tal_steal(c->conn, c);
 
@@ -511,8 +513,8 @@ static struct io_plan *init_hsm(struct io_conn *conn,
 {
 	struct pubkey node_id;
 
-	/* This must be the master. */
-	assert(c == c->master);
+	/* This must be lightningd. */
+	assert(is_lightningd(c));
 
 	/*~ The fromwire_* routines are autogenerated, based on the message
 	 * definitions in hsm_client_wire.csv.  The format of those files is
@@ -1201,7 +1203,7 @@ static struct io_plan *send_pending_client_fd(struct io_conn *conn,
 {
 	int fd = pending_client_fd;
 	/* This must be the master. */
-	assert(master == master->master);
+	assert(is_lightningd(master));
 	assert(fd != -1);
 
 	/* This sanity check shouldn't be necessary, but it's cheap. */
@@ -1229,7 +1231,7 @@ static struct io_plan *pass_client_hsmfd(struct io_conn *conn,
 	struct pubkey id;
 
 	/* This must be lightningd itself. */
-	assert(c == c->master);
+	assert(is_lightningd(c));
 
 	if (!fromwire_hsm_client_hsmfd(msg_in, &id, &dbid, &capabilities))
 		return bad_req(conn, c, msg_in);
@@ -1729,8 +1731,8 @@ int main(int argc, char *argv[])
 	master = new_client(NULL, NULL, 0, HSM_CAP_MASTER | HSM_CAP_SIGN_GOSSIP,
 			    REQ_FD);
 
-	/* We're our own master! */
-	master->master = master;
+	/* First client == lightningd. */
+	assert(is_lightningd(master));
 
 	/* When conn closes, everything is freed. */
 	io_set_finish(master->conn, master_gone, master);