io/fdpass: don't leak fd if conn closes before we write it.

[ccan] / ccan / io / io.h

diff --git a/ccan/io/io.h b/ccan/io/io.h
index a93c6ed49941580efc4741ca58687b062d63c472..5d084828b96aa561bbdfd6fe814ea5461f9342cb 100644 (file)
--- a/ccan/io/io.h
+++ b/ccan/io/io.h
@@ -59,7 +59,7 @@ struct io_conn;
        io_new_conn_((ctx), (fd),                                       \
                     typesafe_cb_preargs(struct io_plan *, void *,      \
                                         (init), (arg),                 \
        io_new_conn_((ctx), (fd),                                       \
                     typesafe_cb_preargs(struct io_plan *, void *,      \
                                         (init), (arg),                 \

-                                        struct io_conn *conn),         \
+                                        struct io_conn *),             \

                     (void *)(arg))
 
 struct io_conn *io_new_conn_(const tal_t *ctx, int fd,
                     (void *)(arg))
 
 struct io_conn *io_new_conn_(const tal_t *ctx, int fd,


@@ -113,6 +113,8 @@ void io_set_finish_(struct io_conn *conn,
  * (tal'ocated off @ctx) and pass that to init().  Note that if there is
  * an error on this file descriptor, it will be freed.
  *
  * (tal'ocated off @ctx) and pass that to init().  Note that if there is
  * an error on this file descriptor, it will be freed.
  *

+ * Note: if the accept fails (usually due to EMFILE), init() will be called
+ * wth

  * Returns NULL on error (and sets errno).
  *
  * Example:
  * Returns NULL on error (and sets errno).
  *
  * Example:


@@ -389,6 +391,39 @@ struct io_plan *io_out_always_(struct io_conn *conn,
                                                       void *),
                               void *arg);
 
                                                       void *),
                               void *arg);
 

+/**
+ * io_sock_shutdown - start socket close process (flushes TCP sockets).
+ * @conn: the connection the plan is for
+ *
+ * Simply closing a TCP socket can lose data; unfortunately you should
+ * shutdown(SHUT_WR) and wait for the other side to see this and close.
+ * Of course, you also need to set a timer, in case it doesn't (you may
+ * already have some responsiveness timer, of course).
+ *
+ * On error, is equivalent to io_close().
+ *
+ * Example:
+ * #include <ccan/timer/timer.h>
+ *
+ * // Timer infra needs wrapper to contain extra data.
+ * struct timeout_timer {
+ *    struct timer t;
+ *    struct io_conn *conn;
+ * };
+ * static struct timers timers;
+ *
+ * static struct io_plan *flush_and_close(struct io_conn *conn)
+ * {
+ *    struct timeout_timer *timeout;
+ *    // Freed if conn closes normally.
+ *    timeout = tal(conn, struct timeout_timer);
+ *    timeout->conn = conn;
+ *    timer_addrel(&timers, &timeout->t, time_from_sec(5));
+ *    return io_sock_shutdown(conn);
+ * }
+ */
+struct io_plan *io_sock_shutdown(struct io_conn *conn);
+

 /**
  * io_connect - create an asynchronous connection to a listening socket.
  * @conn: the connection that plan is for.
 /**
  * io_connect - create an asynchronous connection to a listening socket.
  * @conn: the connection that plan is for.


@@ -734,9 +769,9 @@ bool io_flush_sync(struct io_conn *conn);
  *
  * This allows you to temporarily service only one (or several) fds.
  * For example, you might want to flush out one io_conn and not
  *
  * This allows you to temporarily service only one (or several) fds.
  * For example, you might want to flush out one io_conn and not

- * receive any new connections or read any otherninput.
+ * receive any new connections or read any other input.

  *
  *

- * Returns true of there any exclusive io_conn remain, otherwise false.
+ * Returns true if any exclusive io_conn remain, otherwise false.

  * (This is useful for checking your own logic: dangling exclusive io_conn
  * are dangerous!).
  */
  * (This is useful for checking your own logic: dangling exclusive io_conn
  * are dangerous!).
  */


@@ -781,4 +816,22 @@ struct timemono (*io_time_override(struct timemono (*now)(void)))(void);
  */
 int (*io_poll_override(int (*poll)(struct pollfd *fds, nfds_t nfds, int timeout)))(struct pollfd *, nfds_t, int);
 
  */
 int (*io_poll_override(int (*poll)(struct pollfd *fds, nfds_t nfds, int timeout)))(struct pollfd *, nfds_t, int);
 

+/**
+ * io_have_fd - do we own this file descriptor?
+ * @fd: the file descriptor.
+ * @listener: if non-NULL, set to true if it's a listening socket (io_listener).
+ *
+ * Returns NULL if we don't own it, otherwise a struct io_conn * or struct io_listener *.
+ */
+const void *io_have_fd(int fd, bool *listener);
+
+/**
+ * io_set_extended_errors - enable callbacks for errors.
+ * @state: true or false.
+ *
+ * Defaults false for compatibility.  See io_new_conn for what this changes.
+ */
+void io_set_extended_errors(bool state);
+bool io_get_extended_errors(void);
+

 #endif /* CCAN_IO_H */
 #endif /* CCAN_IO_H */