io: add new io_sock_shutdown helper.

[ccan] / ccan / io / io.c

diff --git a/ccan/io/io.c b/ccan/io/io.c
index 36dcb81e720f448bf46665f93bb40f0692d2256c..12df06d82cb6474fed825cd381f7f225fc6213b1 100644 (file)
--- a/ccan/io/io.c
+++ b/ccan/io/io.c
@@ -529,6 +529,18 @@ bool io_plan_out_started(const struct io_conn *conn)
        return conn->plan[IO_OUT].status == IO_POLLING_STARTED;
 }
 
+/* Despite being a TCP expert, I missed the full extent of this
+ * problem.  The legendary ZmnSCPxj implemented it (with the URL
+ * pointing to the explanation), and I imitate that here. */
+struct io_plan *io_sock_shutdown(struct io_conn *conn)
+{
+       if (shutdown(io_conn_fd(conn), SHUT_WR) != 0)
+               return io_close(conn);
+
+       /* And leave unset .*/
+       return &conn->plan[IO_IN];
+}
+       
 bool io_flush_sync(struct io_conn *conn)
 {
        struct io_plan *plan = &conn->plan[IO_OUT];