X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Flibudev%2Flibudev-monitor.c;h=0212792552f5523097058ef248d42a7ef82d720d;hp=5f448e6d4765f0a086f0c0e0c327c6a61e2dbbe5;hb=491d152dbddb85bc8c309ba24133c99219c8d300;hpb=c8f8394a9309d4390daac70b736b34d0b6734f95

diff --git a/src/libudev/libudev-monitor.c b/src/libudev/libudev-monitor.c
index 5f448e6d4..021279255 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>
@@ -97,23 +105,6 @@ static struct udev_monitor *udev_monitor_new(struct udev *udev)
         return udev_monitor;
 }
 
-/**
- * udev_monitor_new_from_socket:
- * @udev: udev library context
- * @socket_path: unix socket path
- *
- * This function is removed from libudev and will not do anything.
- *
- * Returns: #NULL
- **/
-struct udev_monitor *udev_monitor_new_from_socket(struct udev *udev, const char *socket_path);
-_public_ struct udev_monitor *udev_monitor_new_from_socket(struct udev *udev, const char *socket_path)
-{
-        udev_err(udev, "udev_monitor_new_from_socket() does not do anything; please migrate to netlink\n");
-        errno = ENOSYS;
-        return NULL;
-}
-
 struct udev_monitor *udev_monitor_new_from_netlink_fd(struct udev *udev, const char *name, int fd)
 {
         struct udev_monitor *udev_monitor;
@@ -124,9 +115,9 @@ struct udev_monitor *udev_monitor_new_from_netlink_fd(struct udev *udev, const c
 
         if (name == NULL)
                 group = UDEV_MONITOR_NONE;
-        else if (strcmp(name, "udev") == 0)
+        else if (streq(name, "udev"))
                 group = UDEV_MONITOR_UDEV;
-        else if (strcmp(name, "kernel") == 0)
+        else if (streq(name, "kernel"))
                 group = UDEV_MONITOR_KERNEL;
         else
                 return NULL;
@@ -417,19 +408,21 @@ _public_ struct udev_monitor *udev_monitor_ref(struct udev_monitor *udev_monitor
  * the bound socket will be closed, and the resources of the monitor
  * will be released.
  *
+ * Returns: the passed udev monitor if it has still an active reference, or #NULL otherwise.
  **/
-_public_ void udev_monitor_unref(struct udev_monitor *udev_monitor)
+_public_ struct udev_monitor *udev_monitor_unref(struct udev_monitor *udev_monitor)
 {
         if (udev_monitor == NULL)
-                return;
+                return NULL;
         udev_monitor->refcount--;
         if (udev_monitor->refcount > 0)
-                return;
+                return udev_monitor;
         if (udev_monitor->sock >= 0)
                 close(udev_monitor->sock);
         udev_list_cleanup(&udev_monitor->filter_subsystem_list);
         udev_list_cleanup(&udev_monitor->filter_tag_list);
         free(udev_monitor);
+        return NULL;
 }
 
 /**
@@ -474,7 +467,7 @@ static int passes_filter(struct udev_monitor *udev_monitor, struct udev_device *
                 const char *devtype;
                 const char *ddevtype;
 
-                if (strcmp(dsubsys, subsys) != 0)
+                if (!streq(dsubsys, subsys))
                         continue;
 
                 devtype = udev_list_entry_get_value(list_entry);
@@ -483,7 +476,7 @@ static int passes_filter(struct udev_monitor *udev_monitor, struct udev_device *
                 ddevtype = udev_device_get_devtype(udev_device);
                 if (ddevtype == NULL)
                         continue;
-                if (strcmp(ddevtype, devtype) == 0)
+                if (streq(ddevtype, devtype))
                         goto tag;
         }
         return 0;
@@ -509,6 +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.
  *
@@ -593,7 +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 {