@@ -32,9 +32,47 @@
* rwflags passed to event_ctl and returned by
* struct event_set_return.
*/
-#define EVENT_UNDEF 4
-#define EVENT_READ (1<<0)
-#define EVENT_WRITE (1<<1)
+#define READ_SHIFT 0
+#define WRITE_SHIFT 1
+
+#define EVENT_UNDEF 4
+#define EVENT_READ (1 << READ_SHIFT)
+#define EVENT_WRITE (1 << WRITE_SHIFT)
+
+/* event flags returned by io_wait.
+ *
+ * All these events are defined as bits in a bitfield.
+ * Each event 'type' owns two bits in the bitfield: one for the READ
+ * event and one for the WRITE event.
+ *
+ * For this reason, the specific event bit is calculated by adding
+ * the event type identifier (always a multiple of 2, as defined
+ * below) to 0 for READ and 1 for WRITE.
+ *
+ * E.g.
+ * MANAGEMENT_SHIFT = 6; <---- event type identifier
+ * MANAGEMENT_READ = (1 << (6 + 0)), <---- READ event
+ * MANAGEMENT_WRITE = (1 << (6 + 1)) <---- WRITE event
+ *
+ * 'error' and 'file_close' are special and use read/write for different
+ * signals.
+ */
+
+#define SOCKET_SHIFT 0
+#define SOCKET_READ (1 << (SOCKET_SHIFT + READ_SHIFT))
+#define SOCKET_WRITE (1 << (SOCKET_SHIFT + WRITE_SHIFT))
+#define TUN_SHIFT 2
+#define TUN_READ (1 << (TUN_SHIFT + READ_SHIFT))
+#define TUN_WRITE (1 << (TUN_SHIFT + WRITE_SHIFT))
+#define ERR_SHIFT 4
+#define ES_ERROR (1 << (ERR_SHIFT + READ_SHIFT))
+#define ES_TIMEOUT (1 << (ERR_SHIFT + WRITE_SHIFT))
+#define MANAGEMENT_SHIFT 6
+#define MANAGEMENT_READ (1 << (MANAGEMENT_SHIFT + READ_SHIFT))
+#define MANAGEMENT_WRITE (1 << (MANAGEMENT_SHIFT + WRITE_SHIFT))
+#define FILE_SHIFT 8
+#define FILE_CLOSED (1 << (FILE_SHIFT + READ_SHIFT))
+
/*
* Initialization flags passed to event_set_init
*/
@@ -1867,15 +1867,17 @@ io_wait_dowork(struct context *c, const unsigned int flags)
unsigned int tuntap = 0;
struct event_set_return esr[4];
- /* These shifts all depend on EVENT_READ and EVENT_WRITE */
- static int socket_shift = 0; /* depends on SOCKET_READ and SOCKET_WRITE */
- static int tun_shift = 2; /* depends on TUN_READ and TUN_WRITE */
- static int err_shift = 4; /* depends on ES_ERROR */
+ /* These shifts all depend on EVENT_READ (=1) and EVENT_WRITE (=2)
+ * and are added to the shift. Check openvpn.h for more details.
+ */
+ static int socket_shift = SOCKET_SHIFT;
+ static int tun_shift = TUN_SHIFT;
+ static int err_shift = ERR_SHIFT;
#ifdef ENABLE_MANAGEMENT
- static int management_shift = 6; /* depends on MANAGEMENT_READ and MANAGEMENT_WRITE */
+ static int management_shift = MANAGEMENT_SHIFT;
#endif
#ifdef ENABLE_ASYNC_PUSH
- static int file_shift = 8; /* listening inotify events */
+ static int file_shift = FILE_SHIFT;
#endif
/*
@@ -232,17 +232,7 @@ struct context_2
int event_set_max;
bool event_set_owned;
- /* event flags returned by io_wait */
-#define SOCKET_READ (1<<0)
-#define SOCKET_WRITE (1<<1)
-#define TUN_READ (1<<2)
-#define TUN_WRITE (1<<3)
-#define ES_ERROR (1<<4)
-#define ES_TIMEOUT (1<<5)
-#define MANAGEMENT_READ (1<<6)
-#define MANAGEMENT_WRITE (1<<7)
-#define FILE_CLOSED (1<<8)
-
+ /* bitmask for event status. Check event.h for possible values */
unsigned int event_set_status;
struct link_socket *link_socket; /* socket used for TCP/UDP connection to remote */