ccan: updates to get constant STR_MAX_CHARS and io_close_taken_fd.

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

ccan/README

@@ -1,3 +1,3 @@
 CCAN imported from http://ccodearchive.net.
 
-CCAN version: init-2338-g97ac583
+CCAN version: init-2344-g3f64234

ccan/ccan/io/backend.h

@@ -73,13 +73,13 @@ bool add_listener(struct io_listener *l);
 bool add_conn(struct io_conn *c);
 bool add_duplex(struct io_conn *c);
 void del_listener(struct io_listener *l);
+void cleanup_conn_without_close(struct io_conn *c);
 void backend_new_always(struct io_conn *conn);
 void backend_new_plan(struct io_conn *conn);
 void remove_from_always(struct io_conn *conn);
 void backend_plan_done(struct io_conn *conn);
 
 void backend_wake(const void *wait);
-void backend_del_conn(struct io_conn *conn);
 
 void io_ready(struct io_conn *conn, int pollflags);
 void io_do_always(struct io_conn *conn);

ccan/ccan/io/io.c

@@ -421,6 +421,14 @@ struct io_plan *io_close_cb(struct io_conn *conn, void *next_arg)
 	return io_close(conn);
 }
 
+struct io_plan *io_close_taken_fd(struct io_conn *conn)
+{
+	set_blocking(conn->fd.fd, true);
+
+	cleanup_conn_without_close(conn);
+	return io_close(conn);
+}
+
 /* Exit the loop, returning this (non-NULL) arg. */
 void io_break(const void *ret)
 {

ccan/ccan/io/io.h

@@ -109,7 +109,8 @@ void io_set_finish_(struct io_conn *conn,
  * @arg: the argument to @init.
  *
  * When @fd becomes readable, we accept(), create a new connection,
- * (tal'ocated off @ctx) and pass that to init().
+ * (tal'ocated off @ctx) and pass that to init().  Note that if there is
+ * an error on this file descriptor, it will be freed.
  *
  * Returns NULL on error (and sets errno).
  *
@@ -595,14 +596,16 @@ struct io_plan *io_never(struct io_conn *conn, void *unused);
 /* FIXME: io_recvfrom/io_sendto */
 
 /**
- * io_close - plan to close a connection.
+ * io_close - close a connection.
  * @conn: the connection to close.
  *
- * On return to io_loop, the connection will be closed.  It doesn't have
- * to be the current connection and it doesn't need to be idle.  No more
- * IO or callbacks will occur.
+ * The connection is immediately freed: it doesn't have to be the
+ * current connection and it doesn't need to be idle.  No more IO or
+ * callbacks will occur, but if a function was added by io_set_finish()
+ * it will be called with the current errno preserved.
  *
- * You can close a connection twice without harmful effects.
+ * This is equivalent to tal_free(io_conn), except it returns an io_plan
+ * for use in an io callback.
  *
  * Example:
  * static struct io_plan *close_on_timeout(struct io_conn *conn, const char *msg)
@@ -617,14 +620,34 @@ struct io_plan *io_close(struct io_conn *conn);
  * io_close_cb - helper callback to close a connection.
  * @conn: the connection.
  *
- * This schedules a connection to be closed; designed to be used as
- * a callback function.
+ * This is closes a connection; designed to be used as a callback
+ * function.
  *
  * Example:
  *	#define close_on_timeout io_close_cb
  */
 struct io_plan *io_close_cb(struct io_conn *, void *unused);
 
+/**
+ * io_close_taken_fd - close a connection, but remove the filedescriptor first.
+ * @conn: the connection to take the file descriptor from and close.
+ *
+ * io_close closes the file descriptor underlying the io_conn; this version does
+ * not.  Presumably you have used io_conn_fd() on it beforehand and will take
+ * care of the fd yourself.
+ *
+ * Note that this also turns off O_NONBLOCK on the fd.
+ *
+ * Example:
+ * static struct io_plan *steal_fd(struct io_conn *conn, int *fd)
+ * {
+ *	*fd = io_conn_fd(conn);
+ *	printf("stealing fd %i and closing\n", *fd);
+ *	return io_close_taken_fd(conn);
+ * }
+ */
+struct io_plan *io_close_taken_fd(struct io_conn *conn);
+
 /**
  * io_loop - process fds until all closed on io_break.
  * @timers - timers which are waiting to go off (or NULL for none)
@@ -643,7 +666,10 @@ void *io_loop(struct timers *timers, struct timer **expired);
  * io_conn_fd - get the fd from a connection.
  * @conn: the connection.
  *
- * Sometimes useful, eg for getsockname().
+ * Sometimes useful, eg for getsockname().  Note that the fd is O_NONBLOCK.
+ *
+ * See Also:
+ *	io_close_taken_fd
  */
 int io_conn_fd(const struct io_conn *conn);
 

ccan/ccan/io/poll.c

@@ -86,13 +86,6 @@ static void del_fd(struct fd *fd)
 	}
 	num_fds--;
 	fd->backend_info = -1;
-
-	/* Closing a local socket doesn't wake poll() because other end
-	 * has them open.  See 2.6.  When should I use shutdown()?
-	 * in http://www.faqs.org/faqs/unix-faq/socket/ */
-	shutdown(fd->fd, SHUT_RDWR);
-
-	close(fd->fd);
 }
 
 static void destroy_listener(struct io_listener *l)
@@ -164,11 +157,12 @@ void backend_wake(const void *wait)
 	}
 }
 
-static void destroy_conn(struct io_conn *conn)
+static void destroy_conn(struct io_conn *conn, bool close_fd)
 {
 	int saved_errno = errno;
 
-	close(conn->fd.fd);
+	if (close_fd)
+		close(conn->fd.fd);
 	del_fd(&conn->fd);
 	/* In case it's on always list, remove it. */
 	list_del_init(&conn->always);
@@ -180,14 +174,25 @@ static void destroy_conn(struct io_conn *conn)
 	}
 }
 
+static void destroy_conn_close_fd(struct io_conn *conn)
+{
+	destroy_conn(conn, true);
+}
+
 bool add_conn(struct io_conn *c)
 {
 	if (!add_fd(&c->fd, 0))
 		return false;
-	tal_add_destructor(c, destroy_conn);
+	tal_add_destructor(c, destroy_conn_close_fd);
 	return true;
 }
 
+void cleanup_conn_without_close(struct io_conn *conn)
+{
+	tal_del_destructor(conn, destroy_conn_close_fd);
+	destroy_conn(conn, false);
+}
+
 static void accept_conn(struct io_listener *l)
 {
 	int fd = accept(l->fd.fd, NULL, NULL);
@@ -276,9 +281,14 @@ void *io_loop(struct timers *timers, struct timer **expired)
 				break;
 
 			if (fds[i]->listener) {
+				struct io_listener *l = (void *)fds[i];
 				if (events & POLLIN) {
-					accept_conn((void *)c);
+					accept_conn(l);
 					r--;
+				} else if (events & (POLLHUP|POLLNVAL|POLLERR)) {
+					r--;
+					errno = EBADF;
+					io_close_listener(l);
 				}
 			} else if (events & (POLLIN|POLLOUT)) {
 				r--;

ccan/ccan/str/str.h

@@ -94,7 +94,7 @@ size_t strcount(const char *haystack, const char *needle);
 #if HAVE_TYPEOF
 /* Only a simple type can have 0 assigned, so test that. */
 #define STR_MAX_CHARS_TCHECK_(type_or_expr)		\
-	({ typeof(type_or_expr) x = 0; (void)x; 0; })
+	(sizeof(({ typeof(type_or_expr) x = 0; x; }))*0)
 #else
 #define STR_MAX_CHARS_TCHECK_(type_or_expr) 0
 #endif