X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Flibudev%2Flibudev-monitor.c;h=b02ea8808cf949a41de9caca803dba7e7b859f01;hb=e68893075083a7461b1572233d23fdb23541d630;hp=566e9761aa0eb55beef90384f7faa3e33f36f09a;hpb=c195956988799837b763ab1b9f078e5f0b7f26e6;p=elogind.git

diff --git a/src/libudev/libudev-monitor.c b/src/libudev/libudev-monitor.c
index 566e9761a..b02ea8808 100644
--- a/src/libudev/libudev-monitor.c
+++ b/src/libudev/libudev-monitor.c
@@ -1,13 +1,21 @@
-/*
- * libudev - interface to udev device information
- *
- * Copyright (C) 2008-2010 Kay Sievers <kay.sievers@vrfy.org>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- */
+/***
+  This file is part of systemd.
+
+  Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -494,6 +502,11 @@ tag:
  *
  * Only socket connections with uid=0 are accepted.
  *
+ * The monitor socket is by default set to NONBLOCK. A variant of poll() on
+ * the file descriptor returned by udev_monitor_get_fd() should to be used to
+ * wake up when new devices arrive, or alternatively the file descriptor
+ * switched into blocking mode.
+ *
  * The initial refcount is 1, and needs to be decremented to
  * release the resources of the udev device.
  *
@@ -578,7 +591,7 @@ retry:
                             nlh->magic, htonl(UDEV_MONITOR_MAGIC));
                         return NULL;
                 }
-                if (nlh->properties_off+32 > buflen)
+                if (nlh->properties_off+32 > (size_t)buflen)
                         return NULL;
                 bufpos = nlh->properties_off;
         } else {