util: replace close_nointr_nofail() by a more useful safe_close()

safe_close() automatically becomes a NOP when a negative fd is passed,
and returns -1 unconditionally. This makes it easy to write lines like
this:

        fd = safe_close(fd);

Which will close an fd if it is open, and reset the fd variable
correctly.

By making use of this new scheme we can drop a > 200 lines of code that
was required to test for non-negative fds or to reset the closed fd
variable afterwards.

1 files changed, 4 insertions, 11 deletions

diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c
index 5374db74cb..2d3af2f187 100644
--- a/src/libsystemd-network/sd-dhcp-client.c
+++ b/src/libsystemd-network/sd-dhcp-client.c
@@ -184,9 +184,7 @@ static int client_stop(sd_dhcp_client *client, int error) {
         client->receive_message =
                 sd_event_source_unref(client->receive_message);
 
-        if (client->fd >= 0)
-                close_nointr_nofail(client->fd);
-        client->fd = -1;
+        client->fd = safe_close(client->fd);
 
         client->timeout_resend = sd_event_source_unref(client->timeout_resend);
 
@@ -546,12 +544,8 @@ static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata)
         sd_dhcp_client *client = userdata;
         int r;
 
-        if (client->fd >= 0) {
-                client->receive_message =
-                        sd_event_source_unref(client->receive_message);
-                close_nointr_nofail(client->fd);
-                client->fd = -1;
-        }
+        client->receive_message = sd_event_source_unref(client->receive_message);
+        client->fd = safe_close(client->fd);
 
         client->state = DHCP_STATE_REBINDING;
         client->attempt = 1;
@@ -849,8 +843,7 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
 
                         client->receive_message =
                                 sd_event_source_unref(client->receive_message);
-                        close_nointr_nofail(client->fd);
-                        client->fd = -1;
+                        client->fd = safe_close(client->fd);
                 }
 
                 r = 0;