io: io_close_taken_fd to steal fd from conn.

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

diff --git a/ccan/io/backend.h b/ccan/io/backend.h
index f57d24950a7693554bdb104ba58d0ef81294df14..090bff6fb92bf987520d5a94d72a86de92f20036 100644 (file)
--- a/ccan/io/backend.h
+++ b/ccan/io/backend.h
@@ -79,7 +79,6 @@ 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);

diff --git a/ccan/io/io.h b/ccan/io/io.h
index c1d09963caa9a813bb9560763e1fd07269b8c97f..8efc0024c9d230a580bd7838de4d7ad30503e381 100644 (file)
--- a/ccan/io/io.h
+++ b/ccan/io/io.h
@@ -627,6 +627,24 @@ struct io_plan *io_close(struct io_conn *conn);
  */
 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.
+ *
+ * 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)

diff --git a/ccan/io/poll.c b/ccan/io/poll.c
index bd481e9417a835b8f44291b87682a26d750a647d..98a64f42fbe4336283be8f5371688da439943ac6 100644 (file)
--- a/ccan/io/poll.c
+++ b/ccan/io/poll.c
@@ -157,11 +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);
@@ -173,14 +174,26 @@ 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;
 }
 
+struct io_plan *io_close_taken_fd(struct io_conn *conn)
+{
+       tal_del_destructor(conn, destroy_conn_close_fd);
+       destroy_conn(conn, false);
+       return io_close(conn);
+}
+
 static void accept_conn(struct io_listener *l)
 {
        int fd = accept(l->fd.fd, NULL, NULL);

diff --git a/ccan/io/test/run-21-io_close_taken_fd.c b/ccan/io/test/run-21-io_close_taken_fd.c
new file mode 100644 (file)
index 0000000..5529db0
--- /dev/null
+++ b/ccan/io/test/run-21-io_close_taken_fd.c
@@ -0,0 +1,93 @@
+#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>
+
+#define PORT "65021"
+
+static struct io_listener *l;
+
+static struct io_plan *steal_fd(struct io_conn *conn, int *fd)
+{
+       io_close_listener(l);
+       *fd = io_conn_fd(conn);
+       return io_close_taken_fd(conn);
+}
+
+static int make_listen_fd(const char *port, struct addrinfo **info)
+{
+       int fd, on = 1;
+       struct addrinfo *addrinfo, hints;
+
+       memset(&hints, 0, sizeof(hints));
+       hints.ai_family = AF_UNSPEC;
+       hints.ai_socktype = SOCK_STREAM;
+       hints.ai_flags = AI_PASSIVE;
+       hints.ai_protocol = 0;
+
+       if (getaddrinfo(NULL, port, &hints, &addrinfo) != 0)
+               return -1;
+
+       fd = socket(addrinfo->ai_family, addrinfo->ai_socktype,
+                   addrinfo->ai_protocol);
+       if (fd < 0)
+               return -1;
+
+       setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+       if (bind(fd, addrinfo->ai_addr, addrinfo->ai_addrlen) != 0) {
+               close(fd);
+               return -1;
+       }
+       if (listen(fd, 1) != 0) {
+               close(fd);
+               return -1;
+       }
+       *info = addrinfo;
+       return fd;
+}
+
+int main(void)
+{
+       struct addrinfo *addrinfo = NULL;
+       int i, fd, in_fd, status;
+       char buf[strlen("hellothere")];
+
+       /* This is how many tests you plan to run */
+       plan_tests(15);
+       fd = make_listen_fd(PORT, &addrinfo);
+       l = io_new_listener(NULL, fd, steal_fd, &in_fd);
+       fflush(stdout);
+       if (!fork()) {
+               io_close_listener(l);
+               fd = socket(addrinfo->ai_family, addrinfo->ai_socktype,
+                           addrinfo->ai_protocol);
+               if (fd < 0)
+                       exit(1);
+               if (connect(fd, addrinfo->ai_addr, addrinfo->ai_addrlen) != 0)
+                       exit(2);
+               signal(SIGPIPE, SIG_IGN);
+               for (i = 0; i < strlen("hellothere"); i++) {
+                       if (write(fd, "hellothere" + i, 1) != 1)
+                               break;
+               }
+               close(fd);
+               freeaddrinfo(addrinfo);
+               exit(0);
+       }
+       freeaddrinfo(addrinfo);
+       ok1(io_loop(NULL, NULL) == NULL);
+
+       for (i = 0; i < strlen("hellothere"); i++)
+               ok1(read(in_fd, buf + i, 1) == 1);
+
+       ok1(memcmp(buf, "hellothere", sizeof(buf)) == 0);
+       ok1(wait(&status));
+       ok1(WIFEXITED(status));
+       ok1(WEXITSTATUS(status) == 0);
+
+       /* This exits depending on whether all tests passed */
+       return exit_status();
+}