ccan: update to get close option to io/fdpass.

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

ccan/README

@@ -1,3 +1,3 @@
 CCAN imported from http://ccodearchive.net.
 
-CCAN version: init-2354-g9b3f4ef
+CCAN version: init-2367-ged6dd33

ccan/ccan/io/fdpass/_info

@@ -58,7 +58,7 @@
  *
  *	static struct io_plan *send_stdin(struct io_conn *conn, void *unused)
  *	{
- *		return io_send_fd(conn, STDIN_FILENO, io_close_cb, NULL);
+ *		return io_send_fd(conn, STDIN_FILENO, false, io_close_cb, NULL);
  *	}
  *
  *	static void parent(int sockfd)

ccan/ccan/io/fdpass/fdpass.c

@@ -12,17 +12,21 @@ static int do_fd_send(int fd, struct io_plan_arg *arg)
 			return 0;
 		return -1;
 	}
+	if (arg->u2.s)
+		close(arg->u1.s);
 	return 1;
 }
 
 struct io_plan *io_send_fd_(struct io_conn *conn,
 			    int fd,
+			    bool fdclose,
 			    struct io_plan *(*next)(struct io_conn *, void *),
 			    void *next_arg)
 {
 	struct io_plan_arg *arg = io_plan_arg(conn, IO_OUT);
 
 	arg->u1.s = fd;
+	arg->u2.s = fdclose;
 
 	return io_set_plan(conn, IO_OUT, do_fd_send, next, next_arg);
 }

ccan/ccan/io/fdpass/fdpass.h

@@ -7,6 +7,7 @@
  * io_send_fd - output plan to send a file descriptor
  * @conn: the connection that plan is for.
  * @fd: the file descriptor to pass.
+ * @fdclose: true to close fd after successful sending.
  * @next: function to call output is done.
  * @arg: @next argument
  *
@@ -22,17 +23,17 @@
  * Example:
  * static struct io_plan *fd_to_conn(struct io_conn *conn, int fd)
  * {
- *	// Write fd, then close.
- *	return io_send_fd(conn, fd, io_close_cb, NULL);
+ *	// Write fd, then close conn.
+ *	return io_send_fd(conn, fd, false, io_close_cb, NULL);
  * }
  */
-#define io_send_fd(conn, fd, next, arg)					\
-	io_send_fd_((conn), (fd),					\
+#define io_send_fd(conn, fd, fdclose, next, arg)			\
+	io_send_fd_((conn), (fd), (fdclose),				\
 		    typesafe_cb_preargs(struct io_plan *, void *,	\
 					(next), (arg), struct io_conn *), \
 		    (arg))
 struct io_plan *io_send_fd_(struct io_conn *conn,
-			    int fd,
+			    int fd, bool fdclose,
 			    struct io_plan *(*next)(struct io_conn *, void *),
 			    void *arg);
 

ccan/ccan/io/fdpass/test/run.c

@@ -28,7 +28,7 @@ static struct io_plan *try_writing(struct io_conn *conn, int *pfd)
 
 static struct io_plan *send_fd(struct io_conn *conn, int *pfd)
 {
-	return io_send_fd(conn, pfd[0], try_writing, pfd);
+	return io_send_fd(conn, pfd[0], true, try_writing, pfd);
 }
 
 int main(void)

ccan/ccan/io/io.c

@@ -483,3 +483,37 @@ struct io_plan *io_set_plan(struct io_conn *conn, enum io_direction dir,
 
 	return plan;
 }
+
+bool io_flush_sync(struct io_conn *conn)
+{
+	struct io_plan *plan = &conn->plan[IO_OUT];
+	bool ok;
+
+	/* Not writing?  Nothing to do. */
+	if (plan->status != IO_POLLING)
+		return true;
+
+	/* Synchronous please. */
+	set_blocking(io_conn_fd(conn), true);
+
+again:
+	switch (plan->io(conn->fd.fd, &plan->arg)) {
+	case -1:
+		ok = false;
+		break;
+	/* Incomplete, try again. */
+	case 0:
+		goto again;
+	case 1:
+		ok = true;
+		/* In case they come back. */
+		set_always(conn, IO_OUT, plan->next, plan->next_arg);
+		break;
+	default:
+		/* IO should only return -1, 0 or 1 */
+		abort();
+	}
+
+	set_blocking(io_conn_fd(conn), false);
+	return ok;
+}

ccan/ccan/io/io.h

@@ -673,6 +673,24 @@ void *io_loop(struct timers *timers, struct timer **expired);
  */
 int io_conn_fd(const struct io_conn *conn);
 
+/**
+ * io_flush_sync - (synchronously) complete any outstanding output.
+ * @conn: the connection.
+ *
+ * This is generally used as an emergency escape, for example when we
+ * want to write an error message on a socket before terminating, but it may
+ * be in the middle of existing I/O.  We don't want to service any other
+ * IO, either.
+ *
+ * This returns true if all pending output is complete, false on error.
+ * The next callback is not called on the conn, but will be as soon as
+ * io_loop() is called.
+ *
+ * See Also:
+ *	io_close_taken_fd
+ */
+bool io_flush_sync(struct io_conn *conn);
+
 /**
  * io_time_override - override the normal call for time.
  * @nowfn: the function to call.

ccan/ccan/io/test/run-30-io_flush_sync.c

@@ -0,0 +1,91 @@
+#include <ccan/io/io.h>
+/* Include the C files directly. */
+#include <ccan/io/poll.c>
+#include <ccan/io/io.c>
+#include <ccan/tap/tap.h>
+#include <sys/wait.h>
+#include <stdio.h>
+
+static size_t bytes_written;
+
+/* Should be called multiple times, since only writes 1 byte. */
+static int do_controlled_write(int fd, struct io_plan_arg *arg)
+{
+	ssize_t ret;
+
+	ret = write(fd, arg->u1.cp, 1);
+	if (ret < 0)
+		return -1;
+	bytes_written += ret;
+	arg->u1.cp += ret;
+	arg->u2.s -= ret;
+	return arg->u2.s == 0;
+}
+
+static int do_error(int fd, struct io_plan_arg *arg)
+{
+	errno = 1001;
+	return -1;
+}
+
+static struct io_plan *conn_wait(struct io_conn *conn, void *unused)
+{
+	return io_wait(conn, conn, io_never, NULL);
+}
+
+static struct io_plan *init_conn_writer(struct io_conn *conn, const char *str)
+{
+	struct io_plan_arg *arg = io_plan_arg(conn, IO_OUT);
+
+	arg->u1.const_vp = str;
+	arg->u2.s = strlen(str);
+
+	return io_set_plan(conn, IO_OUT, do_controlled_write, conn_wait, NULL);
+}
+
+static struct io_plan *init_conn_reader(struct io_conn *conn, void *dst)
+{
+	/* Never actually succeeds. */
+	return io_read(conn, dst, 1000, io_never, NULL);
+}
+
+static struct io_plan *init_conn_error(struct io_conn *conn, void *unused)
+{
+	io_plan_arg(conn, IO_OUT);
+	return io_set_plan(conn, IO_OUT, do_error, io_never, NULL);
+}
+
+int main(void)
+{
+	int fd = open("/dev/null", O_RDWR);
+	const tal_t *ctx = tal(NULL, char);
+	struct io_conn *conn;
+
+	/* This is how many tests you plan to run */
+	plan_tests(9);
+
+	conn = io_new_conn(ctx, fd, init_conn_writer, "hello");
+	ok1(bytes_written == 0);
+
+	ok1(io_flush_sync(conn));
+	ok1(bytes_written == strlen("hello"));
+
+	/* This won't do anything */
+	ok1(io_flush_sync(conn));
+	ok1(bytes_written == strlen("hello"));
+
+	/* It's reading, this won't do anything. */
+	conn = io_new_conn(ctx, fd, init_conn_reader, ctx);
+	ok1(io_flush_sync(conn));
+	ok1(bytes_written == strlen("hello"));
+
+	/* Now test error state. */
+	conn = io_new_conn(ctx, fd, init_conn_error, ctx);
+	ok1(!io_flush_sync(conn));
+	ok1(errno == 1001);
+
+	tal_free(ctx);
+
+	/* This exits depending on whether all tests passed */
+	return exit_status();
+}

ccan/ccan/str/hex/hex.h

@@ -70,4 +70,4 @@ static inline size_t hex_data_size(size_t strlen)
 {
 	return strlen / 2;
 }
-#endif /* PETTYCOIN_HEX_H */
+#endif /* CCAN_HEX_H */

ccan/ccan/take/_info

@@ -18,7 +18,7 @@
  *	#include <string.h>
  *
  *	// Dumb basename program and driver.
- *	static char *base(const char *file)
+ *	static char *base(const char *file TAKES)
  *	{
  *		const char *p = strrchr(file, '/');
  *		if (!p) 
@@ -53,6 +53,7 @@ int main(int argc, char *argv[])
 
 	if (strcmp(argv[1], "depends") == 0) {
 		printf("ccan/likely\n");
+		printf("ccan/str\n");
 		return 0;
 	}
 

ccan/ccan/take/take.c

@@ -1,16 +1,22 @@
 /* CC0 (Public domain) - see LICENSE file for details */
 #include <ccan/take/take.h>
 #include <ccan/likely/likely.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 static const void **takenarr;
+static const char **labelarr;
 static size_t max_taken, num_taken;
 static size_t allocfail;
 static void (*allocfailfn)(const void *p);
 
-void *take_(const void *p)
+void *take_(const void *p, const char *label)
 {
+	/* Overallocate: it's better than risking calloc returning NULL! */
+	if (unlikely(label && !labelarr))
+		labelarr = calloc(max_taken+1, sizeof(*labelarr));
+
 	if (unlikely(num_taken == max_taken)) {
 		const void **new;
 
@@ -25,9 +31,16 @@ void *take_(const void *p)
 			return (void *)p;
 		}
 		takenarr = new;
+		/* Once labelarr is set, we maintain it. */
+		if (labelarr)
+			labelarr = realloc(labelarr,
+					   sizeof(*labelarr) * (max_taken+1));
 		max_taken++;
 	}
+	if (unlikely(labelarr))
+		labelarr[num_taken] = label;
 	takenarr[num_taken++] = p;
+
 	return (void *)p;
 }
 
@@ -68,9 +81,23 @@ bool is_taken(const void *p)
 	return find_taken(p) > 0;
 }
 
-bool taken_any(void)
+const char *taken_any(void)
 {
-	return num_taken != 0;
+	static char pointer_buf[32];
+
+	if (num_taken == 0)
+		return NULL;
+
+	/* We're *allowed* to have some with labels, some without. */
+	if (labelarr) {
+		size_t i;
+		for (i = 0; i < num_taken; i++)
+			if (labelarr[i])
+				return labelarr[i];
+	}
+
+	sprintf(pointer_buf, "%p", takenarr[0]);
+	return pointer_buf;
 }
 
 void take_cleanup(void)
@@ -78,6 +105,8 @@ void take_cleanup(void)
 	max_taken = num_taken = 0;
 	free(takenarr);
 	takenarr = NULL;
+	free(labelarr);
+	labelarr = NULL;
 }
 
 void take_allocfail(void (*fn)(const void *p))

ccan/ccan/take/take.h

@@ -3,6 +3,24 @@
 #define CCAN_TAKE_H
 #include "config.h"
 #include <stdbool.h>
+#include <ccan/str/str.h>
+
+#ifdef CCAN_TAKE_DEBUG
+#define TAKE_LABEL(p) __FILE__ ":" stringify(__LINE__) ":" stringify(p)
+#else
+#define TAKE_LABEL(p) NULL
+#endif
+
+/**
+ * TAKES - annotate a formal parameter as being take()-able
+ *
+ * This doesn't do anything, but useful for documentation.
+ *
+ * Example:
+ *	void print_string(const char *str TAKES);
+ *	
+ */
+#define TAKES
 
 /**
  * take - record a pointer to be consumed by the function its handed to.
@@ -12,7 +30,7 @@
  * which is extremely useful for chaining functions.  It works on
  * NULL, for pass-through error handling.
  */
-#define take(p) (take_typeof(p) take_((p)))
+#define take(p) (take_typeof(p) take_((p), TAKE_LABEL(p)))
 
 /**
  * taken - check (and un-take) a pointer was passed with take()
@@ -24,7 +42,7 @@
  *
  * Example:
  *	// Silly routine to add 1
- *	static int *add_one(const int *num)
+ *	static int *add_one(const int *num TAKES)
  *	{
  *		int *ret;
  *		if (taken(num))
@@ -60,7 +78,9 @@ bool is_taken(const void *p);
 /**
  * taken_any - are there any taken pointers?
  *
- * Mainly useful for debugging take() leaks.
+ * Mainly useful for debugging take() leaks.  With CCAN_TAKE_DEBUG, returns
+ * the label where the pointer was passed to take(), otherwise returns
+ * a static char buffer with the pointer value in it.  NULL if none are taken.
  *
  * Example:
  *	static void cleanup(void)
@@ -68,7 +88,7 @@ bool is_taken(const void *p);
  *		assert(!taken_any());
  *	}
  */
-bool taken_any(void);
+const char *taken_any(void);
 
 /**
  * take_cleanup - remove all taken pointers from list.
@@ -112,5 +132,5 @@ void take_allocfail(void (*fn)(const void *p));
 #define take_typeof(ptr)
 #endif
 
-void *take_(const void *p);
+void *take_(const void *p, const char *label);
 #endif /* CCAN_TAKE_H */

ccan/ccan/take/test/run-debug.c

@@ -0,0 +1,34 @@
+#include <stdlib.h>
+#include <stdbool.h>
+
+#define CCAN_TAKE_DEBUG 1
+#include <ccan/take/take.h>
+#include <ccan/take/take.c>
+#include <ccan/tap/tap.h>
+
+int main(void)
+{
+	const char *p = "hi";
+
+	plan_tests(14);
+
+	/* We can take NULL. */
+	ok1(take(NULL) == NULL);
+	ok1(is_taken(NULL));
+	ok1(strstr(taken_any(), "run-debug.c:16:"));
+	ok1(taken(NULL)); /* Undoes take() */
+	ok1(!is_taken(NULL));
+	ok1(!taken(NULL));
+	ok1(!taken_any());
+
+	/* We can take a real pointer. */
+	ok1(take(p) == p);
+	ok1(is_taken(p));
+	ok1(strends(taken_any(), "run-debug.c:25:p"));
+	ok1(taken(p)); /* Undoes take() */
+	ok1(!is_taken(p));
+	ok1(!taken(p));
+	ok1(!taken_any());
+
+	return exit_status();
+}

ccan/ccan/tal/path/path.c

@@ -1,7 +1,6 @@
 /* Licensed under BSD-MIT - see LICENSE file for details */
 #include <ccan/tal/path/path.h>
 #include <ccan/str/str.h>
-#include <ccan/take/take.h>
 #include <ccan/tal/str/str.h>
 #include <sys/types.h>
 #include <sys/stat.h>

ccan/ccan/tal/path/path.h

@@ -20,7 +20,7 @@ char *path_cwd(const tal_t *ctx);
  * Returns NULL and sets errno on error, otherwise returns nul-terminated
  * link contents.
  */
-char *path_readlink(const tal_t *ctx, const char *link);
+char *path_readlink(const tal_t *ctx, const char *link TAKES);
 
 /**
  * path_canon - return the canonical absolute pathname.
@@ -31,7 +31,7 @@ char *path_readlink(const tal_t *ctx, const char *link);
  * path with no symbolic links and no extra separators (ie. as per
  * realpath).
  */
-char *path_canon(const tal_t *ctx, const char *a);
+char *path_canon(const tal_t *ctx, const char *a TAKES);
 
 /**
  * path_simplify - remove double-/, ./ and some ../, plus trailing /.
@@ -42,7 +42,7 @@ char *path_canon(const tal_t *ctx, const char *a);
  * terms or remove symlinks, but it does neaten it by removing extraneous
  * parts.
  */
-char *path_simplify(const tal_t *ctx, const char *a);
+char *path_simplify(const tal_t *ctx, const char *a TAKES);
 
 /**
  * path_join - attach one path to another.
@@ -53,14 +53,14 @@ char *path_simplify(const tal_t *ctx, const char *a);
  * If @a is an absolute path, return a copy of it.  Otherwise, attach
  * @a to @base.
  */
-char *path_join(const tal_t *ctx, const char *base, const char *a);
+char *path_join(const tal_t *ctx, const char *base TAKES, const char *a TAKES);
 
 /**
  * path_pushd - save old dir and change to a new one.
  * @ctx: the context to tal the result from
  * @dir: the directory to return to (can be take())
  */
-struct path_pushd *path_pushd(const tal_t *ctx, const char *dir);
+struct path_pushd *path_pushd(const tal_t *ctx, const char *dir TAKES);
 
 /**
  * path_popd - return to old, path_pushd dir.
@@ -83,7 +83,8 @@ bool path_popd(struct path_pushd *olddir);
  *	char *path = path_rel(NULL, "/tmp", "/");
  *	assert(strcmp(path, "..") == 0);
  */
-char *path_rel(const tal_t *ctx, const char *fromdir, const char *to);
+char *path_rel(const tal_t *ctx,
+	       const char *fromdir TAKES, const char *to TAKES);
 
 /**
  * path_basename - get trailing filename part of path
@@ -102,7 +103,7 @@ char *path_rel(const tal_t *ctx, const char *fromdir, const char *to);
  * See Also:
  *	path_dirname()
  */
-char *path_basename(const tal_t *ctx, const char *path);
+char *path_basename(const tal_t *ctx, const char *path TAKES);
 
 /**
  * path_dirname - get the directory part of path
@@ -114,7 +115,7 @@ char *path_basename(const tal_t *ctx, const char *path);
  * See Also:
  *	path_basename()
  */
-char *path_dirname(const tal_t *ctx, const char *path);
+char *path_dirname(const tal_t *ctx, const char *path TAKES);
 
 /**
  * path_is_abs - is a path absolute?
@@ -149,7 +150,7 @@ bool path_is_dir(const char *path);
  * See Also:
  *	strjoin()
  */
-char **path_split(const tal_t *ctx, const char *path);
+char **path_split(const tal_t *ctx, const char *path TAKES);
 
 /**
  * path_ext_off - get offset of the extension within a pathname.

ccan/ccan/tal/str/str.c

@@ -11,7 +11,6 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <ccan/str/str.h>
-#include <ccan/take/take.h>
 
 char *tal_strdup(const tal_t *ctx, const char *p)
 {

ccan/ccan/tal/str/str.h

@@ -14,7 +14,7 @@
  * @ctx: NULL, or tal allocated object to be parent.
  * @p: the string to copy (can be take()).
  */
-char *tal_strdup(const tal_t *ctx, const char *p);
+char *tal_strdup(const tal_t *ctx, const char *p TAKES);
 
 /**
  * tal_strndup - duplicate a limited amount of a string.
@@ -24,14 +24,14 @@ char *tal_strdup(const tal_t *ctx, const char *p);
  *
  * Always gives a nul-terminated string, with strlen() <= @n.
  */
-char *tal_strndup(const tal_t *ctx, const char *p, size_t n);
+char *tal_strndup(const tal_t *ctx, const char *p TAKES, size_t n);
 
 /**
  * tal_fmt - allocate a formatted string
  * @ctx: NULL, or tal allocated object to be parent.
  * @fmt: the printf-style format (can be take()).
  */
-char *tal_fmt(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
+char *tal_fmt(const tal_t *ctx, const char *fmt TAKES, ...) PRINTF_FMT(2,3);
 
 /**
  * tal_vfmt - allocate a formatted string (va_list version)
@@ -39,7 +39,7 @@ char *tal_fmt(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
  * @fmt: the printf-style format (can be take()).
  * @va: the va_list containing the format args.
  */
-char *tal_vfmt(const tal_t *ctx, const char *fmt, va_list ap)
+char *tal_vfmt(const tal_t *ctx, const char *fmt TAKES, va_list ap)
 	PRINTF_FMT(2,0);
 
 /**
@@ -49,7 +49,7 @@ char *tal_vfmt(const tal_t *ctx, const char *fmt, va_list ap)
  *
  * Returns false on allocation failure.
  */
-bool tal_append_fmt(char **baseptr, const char *fmt, ...) PRINTF_FMT(2,3);
+bool tal_append_fmt(char **baseptr, const char *fmt TAKES, ...) PRINTF_FMT(2,3);
 
 /**
  * tal_append_vfmt - append a formatted string to a talloc string (va_list)
@@ -59,7 +59,7 @@ bool tal_append_fmt(char **baseptr, const char *fmt, ...) PRINTF_FMT(2,3);
  *
  * Returns false on allocation failure.
  */
-bool tal_append_vfmt(char **baseptr, const char *fmt, va_list ap);
+bool tal_append_vfmt(char **baseptr, const char *fmt TAKES, va_list ap);
 
 /**
  * tal_strcat - join two strings together
@@ -67,7 +67,7 @@ bool tal_append_vfmt(char **baseptr, const char *fmt, va_list ap);
  * @s1: the first string (can be take()).
  * @s2: the second string (can be take()).
  */
-char *tal_strcat(const tal_t *ctx, const char *s1, const char *s2);
+char *tal_strcat(const tal_t *ctx, const char *s1 TAKES, const char *s2 TAKES);
 
 enum strsplit {
 	STR_EMPTY_OK,
@@ -110,7 +110,9 @@ enum strsplit {
  *	}
  */
 char **tal_strsplit(const tal_t *ctx,
-		    const char *string, const char *delims, enum strsplit flag);
+		    const char *string TAKES,
+		    const char *delims TAKES,
+		    enum strsplit flag);
 
 enum strjoin {
 	STR_TRAIL,
@@ -140,7 +142,9 @@ enum strjoin {
  *		return ret;
  *	}
  */
-char *tal_strjoin(const void *ctx, char *strings[], const char *delim,
+char *tal_strjoin(const void *ctx,
+		  char *strings[] TAKES,
+		  const char *delim TAKES,
 		  enum strjoin flags);
 
 /**
@@ -183,5 +187,6 @@ char *tal_strjoin(const void *ctx, char *strings[], const char *delim,
  *		return 0;
  *	}
  */
-bool tal_strreg(const void *ctx, const char *string, const char *regex, ...);
+bool tal_strreg(const void *ctx, const char *string TAKES,
+		const char *regex TAKES, ...);
 #endif /* CCAN_STR_TAL_H */

ccan/ccan/tal/tal.c

@@ -2,7 +2,6 @@
 #include <ccan/tal/tal.h>
 #include <ccan/compiler/compiler.h>
 #include <ccan/list/list.h>
-#include <ccan/take/take.h>
 #include <ccan/alignof/alignof.h>
 #include <assert.h>
 #include <stdio.h>

ccan/ccan/tal/tal.h

@@ -6,6 +6,7 @@
 #include <ccan/likely/likely.h>
 #include <ccan/typesafe_cb/typesafe_cb.h>
 #include <ccan/str/str.h>
+#include <ccan/take/take.h>
 #include <stdlib.h>
 #include <stdbool.h>
 #include <stdarg.h>
@@ -487,14 +488,14 @@ void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear,
 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
 		     bool add_length, const char *label);
 
-void *tal_dup_(const tal_t *ctx, const void *p, size_t size,
+void *tal_dup_(const tal_t *ctx, const void *p TAKES, size_t size,
 	       size_t n, size_t extra, bool add_length,
 	       const char *label);
 
 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
 
 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear);
-bool tal_expand_(tal_t **ctxp, const void *src, size_t size, size_t count);
+bool tal_expand_(tal_t **ctxp, const void *src TAKES, size_t size, size_t count);
 
 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
 bool tal_add_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),

lightningd/gossip/gossip.c

@@ -406,7 +406,11 @@ static struct io_plan *new_peer(struct io_conn *conn, struct daemon *daemon,
 
 static struct io_plan *release_peer_fd(struct io_conn *conn, struct peer *peer)
 {
-	return io_send_fd(conn, peer->fd, next_req_in, peer->daemon);
+	int fd = peer->fd;
+
+	/* This will be closed after sending. */
+	peer->fd = -1;
+	return io_send_fd(conn, fd, true, next_req_in, peer->daemon);
 }
 
 static struct io_plan *release_peer(struct io_conn *conn, struct daemon *daemon,

lightningd/hsm/hsm.c

@@ -319,17 +319,15 @@ static struct io_plan *recv_req(struct io_conn *conn, struct conn_info *ci)
 	return io_read_wire(conn, ci, &ci->in, ci->received_req, ci);
 }
 
-static struct io_plan *sent_out_fd(struct io_conn *conn, struct conn_info *ci)
-{
-	ci->out_fd = -1;
-	return recv_req(conn, ci);
-}
-
 static struct io_plan *sent_resp(struct io_conn *conn, struct conn_info *ci)
 {
 	ci->out = tal_free(ci->out);
-	if (ci->out_fd != -1)
-		return io_send_fd(conn, ci->out_fd, sent_out_fd, ci);
+	if (ci->out_fd != -1) {
+		int fd = ci->out_fd;
+		ci->out_fd = -1;
+		/* Close after sending */
+		return io_send_fd(conn, fd, true, recv_req, ci);
+	}
 	return recv_req(conn, ci);
 }
 

lightningd/subd.c

@@ -293,11 +293,6 @@ static struct io_plan *msg_send_next(struct io_conn *conn, struct subd *sd)
 {
 	const u8 *msg = msg_dequeue(&sd->outq);
 
-	if (sd->fd_to_close != -1) {
-		close(sd->fd_to_close);
-		sd->fd_to_close = -1;
-	}
-
 	/* Nothing to do?  Wait for msg_enqueue. */
 	if (!msg)
 		return msg_queue_wait(conn, &sd->outq, msg_send_next, sd);
@@ -306,9 +301,9 @@ static struct io_plan *msg_send_next(struct io_conn *conn, struct subd *sd)
 	if (fromwire_peektype(msg) == STATUS_TRACE) {
 		const u8 *p = msg + sizeof(be16);
 		size_t len = tal_count(msg) - sizeof(be16);
-		sd->fd_to_close = fromwire_u32(&p, &len);
+		int fd = fromwire_u32(&p, &len);
 		tal_free(msg);
-		return io_send_fd(conn, sd->fd_to_close, msg_send_next, sd);
+		return io_send_fd(conn, fd, true, msg_send_next, sd);
 	}
 	return io_write_wire(conn, take(msg), msg_send_next, sd);
 }
@@ -353,7 +348,6 @@ struct subd *new_subd(const tal_t *ctx,
 	sd->msgcb = msgcb;
 	sd->fd_in = -1;
 	msg_queue_init(&sd->outq, sd);
-	sd->fd_to_close = -1;
 	tal_add_destructor(sd, destroy_subd);
 	list_head_init(&sd->reqs);
 

lightningd/subd.h

@@ -47,9 +47,6 @@ struct subd {
 	/* Messages queue up here. */
 	struct msg_queue outq;
 
-	/* FD to close (used when we just sent it). */
-	int fd_to_close;
-
 	/* Callbacks for replies. */
 	struct list_head reqs;
 };