Process RFKILL events after opening device

To avoid the case when RFKILL event happens in the device enable stage,
process the initial events after opening the device. The /dev/rfkill
sends out the current RFKIL states after open(). This fixes a race
condition between device enabling and initial RFKILL states.

diff --git a/src/rfkill.c b/src/rfkill.c
index 4b6a61d..fd38db9 100644 (file)
--- a/src/rfkill.c
+++ b/src/rfkill.c
@@ -56,34 +56,31 @@ struct rfkill_event {
        uint8_t  hard;
 };
 
-static gboolean rfkill_event(GIOChannel *chan,
-                               GIOCondition cond, gpointer data)
+static GIOStatus rfkill_process(GIOChannel *chan)
 {
+       GIOStatus status = G_IO_STATUS_NORMAL;
        unsigned char buf[32];
        struct rfkill_event *event = (void *) buf;
        char sysname[32];
        connman_bool_t blocked;
        gsize len;
-       GIOError err;
 
-       if (cond & (G_IO_NVAL | G_IO_HUP | G_IO_ERR))
-               return FALSE;
+       DBG("");
 
        memset(buf, 0, sizeof(buf));
 
-       err = g_io_channel_read(chan, (gchar *) buf, sizeof(buf), &len);
-       if (err) {
-               if (err == G_IO_ERROR_AGAIN)
-                       return TRUE;
-               return FALSE;
-       }
+       status = g_io_channel_read_chars(chan, (gchar *) buf,
+                       sizeof(struct rfkill_event), &len, NULL);
+
+       if (status != G_IO_STATUS_NORMAL)
+               return status;
 
        if (len != sizeof(struct rfkill_event))
-               return TRUE;
+               return status;
 
        DBG("idx %u type %u op %u soft %u hard %u",
-                                       event->idx, event->type, event->op,
-                                               event->soft, event->hard);
+                               event->idx, event->type, event->op,
+                                       event->soft, event->hard);
 
        snprintf(sysname, sizeof(sysname) - 1, "rfkill%d", event->idx);
 
@@ -98,6 +95,21 @@ static gboolean rfkill_event(GIOChannel *chan,
                break;
        }
 
+       return status;
+}
+
+static gboolean rfkill_event(GIOChannel *chan,
+                               GIOCondition cond, gpointer data)
+{
+       GIOStatus status;
+
+       if (cond & (G_IO_NVAL | G_IO_HUP | G_IO_ERR))
+               return FALSE;
+
+       status = rfkill_process(chan);
+       if (status == G_IO_STATUS_ERROR)
+               return FALSE;
+
        return TRUE;
 }
 
@@ -105,6 +117,7 @@ static GIOChannel *channel = NULL;
 
 int __connman_rfkill_init(void)
 {
+       GIOFlags flags;
        int fd;
 
        DBG("");
@@ -118,6 +131,14 @@ int __connman_rfkill_init(void)
        channel = g_io_channel_unix_new(fd);
        g_io_channel_set_close_on_unref(channel, TRUE);
 
+       flags = g_io_channel_get_flags(channel);
+       flags |= G_IO_FLAG_NONBLOCK;
+       g_io_channel_set_flags(channel, flags, NULL);
+
+       /* Process current RFKILL events sent on device open */
+       while (rfkill_process(channel) == G_IO_STATUS_NORMAL)
+               ;
+
        g_io_add_watch(channel, G_IO_IN | G_IO_NVAL | G_IO_HUP | G_IO_ERR,
                                                        rfkill_event, NULL);